Showing papers on "Sequence analysis published in 1985"
TL;DR: It is speculated that the Notch locus may be involved in a cell-cell interaction mechanism that is essential for the differentiation of the ectoderm into neural and epidermal precursors.
1,061 citations
TL;DR: The sequence of the bovine delta-sub unit of F1-ATPase shows that it is the counterpart of the bacterial epsilon-subunit, which is not related to any known bacterial or chloroplast H+- ATPase subunit.
469 citations
TL;DR: A new family of ras genes is identified, the rho genes, which share several properties with the more classical ras gene family consisting of N-, K-, and H-ras, suggesting that the two proteins may share common functions but may use these functions in different ways.
459 citations
TL;DR: A rapid and versatile method has been developed for the synthesis of oligonucleotides which contain an aliphatic amino group at their 5' terminus that reacts specifically with a variety of electrophiles, thereby allowing other chemical species to be attached to the oligon nucleotide.
Abstract: A rapid and versatile method has been developed for the synthesis of oligonucleotides which contain an aliphatic amino group at their 5' terminus. This amino group reacts specifically with a variety of electrophiles, thereby allowing other chemical species to be attached to the oligonucleotide. This chemistry has been utilized to synthesize several fluorescent derivatives of an oligonucleotide primer used in DNA sequence analysis by the dideoxy (enzymatic) method. The modified primers are highly fluorescent and retain their ability to specifically prime DNA synthesis. The use of these fluorescent primers in DNA sequence analysis will enable DNA sequence analysis to be automated.
408 citations
TL;DR: Clones containing heat-inducible mRNA sequences were selected from a cDNA library prepared from polyadenylated RNA isolated from heat-shocked chicken embryo fibroblasts and DNA sequence analysis indicated its protein product has amino acid sequences identical to bovine ubiquitin.
Abstract: Clones containing heat-inducible mRNA sequences were selected from a cDNA library prepared from polyadenylated RNA isolated from heat-shocked chicken embryo fibroblasts. One recombinant DNA clone, designated clone 7, hybridized to a 1.2-kilobase RNA that was present in normal cells and increased fivefold during heat shock. Clone 7 also hybridized to an RNA species of 1.7 kilobases that was present exclusively in heat-shocked cells. In vitro translation of mRNA hybrid selected from clone 7 produced a protein product with a molecular weight of approximately 8,000. Increased synthesis of a protein of similar size was detected in chicken embryo fibroblasts after heat shock. DNA sequence analysis of clone 7 indicated its protein product has amino acid sequences identical to bovine ubiquitin. In addition, clone 7 contains tandem copies of the ubiquitin sequences contiguous to each other with no untranslated sequences between them. We discuss some possible roles for ubiquitin in the heat shock response.
392 citations
TL;DR: The isolation of a complementary DNA clone encoding rat TGF-α, a 50-amino acid polypeptide that is present not only in retrovirus-transformed rat cells but also at lower levels in normal rat tissues, is reported.
Abstract: Transforming growth factors (TGFs) are mitogenic polypeptides produced most conspicuously by transformed cells and conferring on normal cells several phenotypic alterations associated with transformation1,2. TGFs comprise two distinct sets of molecules: TGF-αs are structurally similar to epidermal growth factor (EGF), binding to and inducing the tyrosine phosphorylation of the EGF receptor in a manner indistinguishable from that of EGF3. In addition, the 50-amino acid rat TGF-α4 has 33 and 44% homologies with mouse5 and human6 EGFs, respectively, and shares with EGFs a conserved pattern of three disulphide bridges7. Thus, it has been proposed that TGF-αs belong to a family of EGF-like polypeptides7. TGF-βs, on the other hand, display no measurable binding to EGF receptors, but potentiate the growth stimulating activities of TGF-α8. Here we report the isolation of a complementary DNA clone encoding rat TGF-α. This cDNA hybridizes to a 4.5-kilobase (kb) messenger RNA that is 30 times larger than necessary to code for a 50-amino acid polypeptide and is present not only in retrovirus-transformed rat cells but also at lower levels in normal rat tissues. The nucleotide sequence of the cDNA predicts that TGF-α is synthesized as a larger product and that the larger form may exist as a transmembrane protein. However, unlike many polypeptide hormones (including EGF9,10), cleavage of the 50-amino acid TGF-α from the larger form does not occur at paired basic residues, but rather between alanine and valine residues, suggesting the role of a novel protease.
345 citations
TL;DR: A high degree of sequence homology was observed between human cathepsin D and other aspartyl proteases, suggesting a conservation of three-dimensional structure in this family of proteins.
Abstract: An 1110-base-pair cDNA clone for human cathepsin D was obtained by screening a lambda gt10 human hepatoma G2 cDNA library with a human renin exon 3 genomic fragment. Poly(A)+ RNA blot analysis with this cathepsin D clone demonstrated a message length of about 2.2 kilobases. The partial clone was used to screen a size-selected human kidney cDNA library, from which two cathepsin D recombinant plasmids with inserts of about 2200 and 2150 base pairs were obtained. The nucleotide sequences of these clones and of the lambda gt10 clone were determined. The amino acid sequence predicted from the cDNA sequence shows that human cathepsin D consists of 412 amino acids with 20 and 44 amino acids in a pre- and a prosegment, respectively. The mature protein region shows 87% amino acid identity with porcine cathepsin D but differs in having nine additional amino acids. Two of these are at the COOH terminus; the other seven are positioned between the previously determined junction for the light and heavy chains of porcine cathepsin D. A high degree of sequence homology was observed between human cathepsin D and other aspartyl proteases, suggesting a conservation of three-dimensional structure in this family of proteins.
308 citations
TL;DR: This work isolated the p36-p10 complex from bovine intestinal epithelium and analyzed the amino terminus of both subunits, establishing the site of tyrosine phosphorylation.
Abstract: p36 is a major substrate of both viral and growth factor-receptor-associated tyrosine protein kinases. p36 can be isolated as a complex consisting of a subunit of Mr 36,000 (p36) and a subunit of Mr 10,000 (p10), and it represents an abundant cellular protein. We have isolated the p36-p10 complex from bovine intestinal epithelium and analyzed the amino terminus of both subunits. Sequence analysis of the first 56 amino acids of p10 demonstrates a striking sequence homology (48% identically placed residues) with the Mr 10,000 calcium-binding proteins from bovine brain, termed S-100. Intestinal p36 could be effectively labeled on a single tyrosine in vitro with immunoprecipitated pp60v-src and [gamma-32P]ATP. Mild proteolysis of p36 with chymotrypsin resulted in the cleavage into large (Mr, 33,000) and small domains (Mr, 3000), with the latter representing the phosphorylated amino terminus. Although the amino terminus is apparently blocked, sequence analysis of a secondary tryptic peptide of the Mr 3000 fragment as well as the amino-terminal sequence of the Mr 33,000 domain and overlapping peptides clearly established the site of tyrosine phosphorylation.
257 citations
TL;DR: Two distinct classes of cDNA clones that can each independently transform mouse C127 cells are identified that contain the E2 ORF intact and the second contains the E6 OrF intact, and these two putative viral functions appear to act synergistically in transforming mouse C 127 cells in vitro.
Abstract: Bovine papillomavirus type 1 (BPV-1) and its cloned full-length DNA can transform rodent cells in vitro, and the viral DNA persists as an extrachromosomal multicopy plasmid in these transformed cells. Previous studies have identified at least five discrete viral RNAs that are expressed in BPV-1 transformed cells and have shown that these transcripts share a 3' coterminus. To further define the structure of these RNAs and to characterize the functions of individual viral transcripts, we constructed a cDNA library with mRNA from BPV-1-transformed mouse C127 cells using an Okayama and Berg plasmid. From a library of 10(5) independent clones, 200 BPV-1 specific clones were isolated and characterized. Sequence analysis has revealed differential splicing patterns for the mRNA species in BPV-1 transformed cells. In conjunction with the open reading frames (ORFs) deduced from the BPV-1 DNA sequence, it is possible to predict the structure of the potential encoded proteins. The vector used to generate these cDNA clones contains mammalian cell transcriptional regulatory elements, facilitating their functional characterization. We have identified two distinct classes of cDNA clones that can each independently transform mouse C127 cells. One class of cDNA clones contains the E2 ORF intact and the second contains the E6 ORF intact. These two putative viral functions appear to act synergistically in transforming mouse C127 cells in vitro.
250 citations
TL;DR: It is suggested that XK81 functions specifically in the differentiation of the tadpole epidermis, and provides an example of a cytokeratin whose expression is limited to pre-adult developmental stages.
Abstract: DG81 is a cDNA clone derived from a subtracted library containing those RNA molecules that are present in gastrulae but absent from eggs of the frog Xenopus laevis. DG RNAs (where DG indicates differentially expressed in gastrula) represent the products of new transcription activated in the embryo at the midblastula transition or shortly thereafter. DG81 RNA is first detected in middle to late gastrulae, peaks in abundance in early tadpoles, and declines to background levels by the end of metamorphosis. Sequence analysis of an almost full-length cDNA clone homologous to DG81 allows deduction of a protein sequence that shows extensive homology to known intermediate filament proteins, most notably to epidermal type I cytokeratins. Consequently, the protein encoded by DG81 has been named XK81, for Xenopus keratin 81. In concert with keratins analyzed previously, XK81 has a central coiled-coil alpha-helical domain of 312 amino acids, which accounts for most of the homology to other keratins. This rod-like region is flanked by more divergent domains of 73 amino acids at the NH2 terminus and 44 amino acids at the COOH terminus. XK81 provides an example of a cytokeratin whose expression is limited to pre-adult developmental stages. We suggest that XK81 functions specifically in the differentiation of the tadpole epidermis.
240 citations
TL;DR: A collection of human Y-derived cosmid clones was screened with a plasmid insert containing a member of the human X chromosome alphoid repeat family, DXZ1, and a 5500 base EcoRI fragment was found to be characteristic of a Y-specific alphoids repeat.
TL;DR: Nucleotide sequence analysis of the cloned cDNA has revealed that rat prepro‐CRF consists of 187 amino acid residues including a putative signal peptide.
TL;DR: The results suggest a strong similarity in the pathways for indoleacetic acid synthesis encoded by genes in P. savastanoi and in A. tumefaciens T-DNA.
Abstract: We report the nucleotide sequences of iaaM and iaaH, the genetic determinants for, respectively, tryptophan 2-monooxygenase and indoleacetamide hydrolase, the enzymes that catalyze the conversion of L-tryptophan to indoleacetic acid in the tumor-forming bacterium Pseudomonas syringae pv. savastanoi. The sequence analysis indicates that the iaaM locus contains an open reading frame encoding 557 amino acids that would comprise a protein with a molecular weight of 61,783; the iaaH locus contains an open reading frame of 455 amino acids that would comprise a protein with a molecular weight of 48,515. Significant amino acid sequence homology was found between the predicted sequence of the tryptophan monooxygenase of P. savastanoi and the deduced product of the T-DNA tms-1 gene of the octopine-type plasmid pTiA6NC from Agrobacterium tumefaciens. Strong homology was found in the 25 amino acid sequence in the putative FAD-binding region of tryptophan monooxygenase. Homology was also found in the amino acid sequences representing the central regions of the putative products of iaaH and tms-2 T-DNA. The results suggest a strong similarity in the pathways for indoleacetic acid synthesis encoded by genes in P. savastanoi and in A. tumefaciens T-DNA.
TL;DR: In this article, the authors reported successful cloning of sequences between 0.398 to 0.413 in an undeleted form, using a yeast cloning vector, using sequence analysis of a 425-base pair fragment spanning the deletion-prone region.
Abstract: The herpes simplex virus type 1 genome (160 kilobases) contains three origins of DNA synthesis: two copies of oriS located within the repeated sequences flanking the short unique arm (US), and one copy of oriL located within the long unique arm (UL). Precise localization and characterization of oriL have been severely hampered by the inability to clone sequences which contain it (coordinates 0.398 to 0.413) in an undeleted form in bacteria. We report herein the successful cloning of sequences between 0.398 to 0.413 in an undeleted form, using a yeast cloning vector. Sequence analysis of a 425-base pair fragment spanning the deletion-prone region has revealed a perfect 144-base pair palindrome with striking homology to oriS. In a functional assay, the undeleted clone was amplified when functions from herpes simplex virus type 1 were supplied in trans, whereas clones with deletions of 55 base pairs or more were not amplified.
TL;DR: It was found that the products of genes US4, US5 and US7 were convincingly classified as membrane-translated, while the US2 product gave a less definitive result.
TL;DR: To establish whether the Iμ transcripts have any translational potential and to elucidate the structure of their promoter region, sequence analysis of cloned Iμ complementary DNAs, primer extension and S1, nuclease mapping has found that these transcripts have remarkable 5′ heterogeneity.
Abstract: Transcriptional competence of the immunoglobulin heavy-chain locus (IgH) is established at an early stage of lymphoid cell development, leading to the appearance of RNA components, previously called Cμ RNA1 or sterile-μ RNA2, which contain constant-region sequences but lack variable-region sequences. These components are of two types: those which initiate in the D region of alleles that have undergone DJH (diversity–joining region) rearrangement (Dμ transcripts) and those which initiate within the JH–Cμ intron (hereafter termed Iμ transcripts)3,4. In pre-B and early B cells, Dμ and lμ transcripts are nearly as abundant as the messenger RNA encoding μ heavy chain2,3,5. The Dμ transcripts are spliced into RNAs containing D, JH and Cμ sequences, and in some, but not all, cases these RNAs are translated into Dμ proteins4. To establish whether the Iμ transcripts have any translational potential and to elucidate the structure of their promoter region, we have determined their transcription initiation sites and their mode of splicing. As reported here, by using sequence analysis of cloned Iμ complementary DNAs, primer extension and S1, nuclease mapping, we have found that these transcripts have remarkable 5′ heterogeneity: ther e are more than five distinct start sites spanning a region of 44 nucleotides that is located downstream of an octanucleotide found in all variable-region promoters. Such imprecise initiation may result from the lack of a well-defined T A T AA motif and the unusual proximity of the octanucleotide to the enhancer region. Approximately 700 nucleotides downstream from these initiation sites, a cryptic splice site is used to create a nontranslatable exon (‘nontron’) which is joined to the Cμ1 domain. The properties of the nontron may be important for the mechanism of allelic exclusion.
TL;DR: The cloning, expression and sequence analysis of murine IL-2 cDNAs are reported and it is reported that the longest cDNA insert encodes a polypeptide of 169 amino acids, containing unique repeats of a CAG sequence which would encode 12 consecutive glutamine residues within the activeIL-2 molecule.
Abstract: Interleukin-2 (IL-2) is a lymphokine originally described as a humoral factor required for the continued proliferation of activated T-cell clones. It also seems to be involved in the mitogenic response of thymocytes, in augmenting natural killer cell activity, in the generation of cytotoxic T cells and in the induction of other lymphokines such as gamma-interferon and a B-cell growth factor (BCGF-1). More recently, there has been evidence for the involvement of IL-2 per se in the stimulation of B-cell growth (ref. 10 and T. Kishimoto and J. Vilcek, personal communications). We have reported previously the cloning and expression of a human IL-2 complementary DNA. The cDNA encodes biologically active IL-2 which would consist of 153 amino acids, including a signal sequence. Because so much of the work on IL-2 has been done in the human and mouse, we sought to obtain cDNA encoding murine IL-2, and we now report the cloning, expression and sequence analysis of murine IL-2 cDNAs. The longest cDNA insert encodes a polypeptide of 169 amino acids, containing unique repeats of a CAG sequence which would encode 12 consecutive glutamine residues within the active IL-2 molecule.
TL;DR: Application of these methods to a well-documented case of gene conversion in human gamma-globin genes shows that sites corresponding to two of the three observed partitions are significantly clustered, whereas application to hominoid mitochondrial DNA sequences--among which no recombination is expected to occur-- shows no evidence of such clustering.
Abstract: Simple but exact statistical tests for detecting a cluster of associated nucleotide changes in DNA are presented. The tests are based on the linear distribution of a set of s sites among a total of n sites, where the s sites may be the variable sites, sites of insertion/deletion, or categorized in some other way. These tests are especially useful for detecting gene conversion and intragenic recombination in a sample of DNA sequences. In this case, the sites of interest are those that correspond to particular ways of splitting the sequences into two groups (e.g., sequences A and D vs. sequences B, C, and E-J). Each such split is termed a phylogenetic partition. Application of these methods to a well-documented case of gene conversion in human gamma-globin genes shows that sites corresponding to two of the three observed partitions are significantly clustered, whereas application to hominoid mitochondrial DNA sequences--among which no recombination is expected to occur--shows no evidence of such clustering. This indicates that clustering of partition-specific sites is largely due to intragenic recombination or gene conversion. Alternative hypotheses explaining the observed clustering of sites, such as biased selection or mutation, are discussed.
TL;DR: Study of RNA extracted from cells both entering stationary phase and undergoing synchronous cell divisions suggests that commitment to the cell cycle is not controlled by regulation of cdc10 transcript level.
Abstract: The cdc10 'start' gene from the fission yeast Schizosaccharomyces pombe has been cloned by rescue of mutant function. It is present as a single copy in the haploid genome. Hybridisation of the gene to Northern blots has identified a low abundance 2.7-kb polyadenylated RNA. Study of RNA extracted from cells both entering stationary phase and undergoing synchronous cell divisions suggests that commitment to the cell cycle is not controlled by regulation of cdc10 transcript level. DNA sequence analysis of the gene has identified an open reading frame capable of encoding a protein of mol. wt. 85 400. The putative cdc10 gene product shows no significant primary structure similarity with products of other fission and budding yeast cell cycle genes, or with other protein sequences in several databases.
TL;DR: Computer analyses of the amino acid sequences have provided predictions regarding a number of structural features of the phytochrome molecule.
Abstract: Cloned cDNA and genomic sequences have been analyzed to deduce the amino acid sequence of phytochrome from etiolated Avena. Restriction endonuclease site polymorphism between clones indicates that at least four phytochrome genes are expressed in this tissue. Sequence analysis of two complete and one partial coding region shows approximately 98% homology at both the nucleotide and amino acid levels, with the majority of amino acid changes being conservative. High sequence homology is also found in the 5'-untranslated region but significant divergence occurs in the 3'-untranslated region. The phytochrome polypeptides are 1128 amino acid residues long corresponding to a molecular mass of 125 kdaltons. The known protein sequence at the chromophore attachment site occurs only once in the polypeptide, establishing that phytochrome has a single chromophore per monomer covalently linked to Cys-321. Computer analyses of the amino acid sequences have provided predictions regarding a number of structural features of the phytochrome molecule.
TL;DR: The 44-residue C-terminal extension of PLAP has a stretch of 17 hydrophobic amino acids, which presumably anchors the protein to the plasma membrane, a change perhaps necessary for the transition from a bacterial periplasmic enzyme to a mammalian membrane-associated enzyme.
Abstract: A human term (third trimester) placental alkaline phosphatase (PLAP; EC 3.1.3.1) cDNA was isolated from a human placental lambda gt11 cDNA library. The expression library was screened by using rabbit antibodies against PLAP and oligonucleotide probes. DNA sequence analysis of a positive clone with an insert of 2.7 kilobase pairs allowed us to predict the complete amino acid sequence of PLAP (530 residues), which coincided with the reported 42 N-terminal amino acid sequence of PLAP except at position 3. Contrary to the previous supposition that there was no amino acid sequence homology between PLAP and Escherichia coli alkaline phosphatase (471 residues), we found 30% overall homology, with regions of strong homology including the putative active site and the metal-binding sites. The 44-residue C-terminal extension of PLAP has a stretch of 17 hydrophobic amino acids, which presumably anchors the protein to the plasma membrane, a change perhaps necessary for the transition from a bacterial periplasmic enzyme to a mammalian membrane-associated enzyme. We have also localized PLAP-related DNA sequences mainly on chromosome 2 and to a lesser degree on chromosome 17. It seems likely therefore that the PLAP gene resides on chromosome 2 and other member(s) of the alkaline phosphatase family may exist (on this chromosome and) on chromosome 17.
TL;DR: Full-length double-stranded cDNA was prepared from purified circular RNA of two new Australian field isolates of citrus exocortis viroid and indicated that both isolates consisted of a mixture of viroid species and led to the discovery of eleven new sequence variants of CEV.
Abstract: Full-length double-stranded cDNA was prepared from purified circular RNA of two new Australian field isolates of citrus exocortis viroid (CEV) using two synthetic oligodeoxynucleotide primers. The cDNA was then cloned into the phage vector M13mp9 for sequence analysis. Sequencing of nine cDNA clones of isolate CEV-DE30 and eleven cDNA clones of isolate CEV-J indicated that both isolates consisted of a mixture of viroid species and led to the discovery of eleven new sequence variants of CEV. These new variants, together with the six reported previously, form two classes of sequence which differ by a minimum of 26 nucleotides in a total of 370 to 375 residues. These two classes correlate with two biologically distinct groups when propagated on tomato plants where one produces severe symptoms and the other gives rise to mild symptoms. Two regions of the native structure of CEV, comprising 18% of the total residues, differ between the sequence variants of mild and severe isolates. Whether or not both of these regions are essential for the variation in pathogenicity has yet to be determined.
TL;DR: Within the predicted amino acid sequence of factor XII, it is identified three peptide bonds that are cleaved by kallikrein during the formation of beta-factor XIIa, which is proposed based on the known high resolution x-ray diffraction structures of trypsin, chymotrypsin and elastase.
TL;DR: The sequence determination together with the S1 nuclease mapping and RNA blot-hybridization analyses indicate that human HMW and LMW prekininogen mRNAs share an identical sequence throughout the 5'-untranslated region and the protein-coding region up to the sequence encoding the 12 amino acids distal to the bradykinin sequence, and the two m RNAs then completely diverge from each other.
TL;DR: DNA sequence data, RNA hybridization analysis, and hybrid released in vitro translation indicate that the cDNA clone pDC11 encodes extensin and that cDNA clones pDC12 and pDC16 encode the 33-kDa peptide, which as yet has an unknown identity and function.
Abstract: Extensins are hydroxyproline-rich glycoproteins associated with most dicotyledonous plant cell walls. To isolate cDNA clones encoding extensin, we started by isolating poly(A)+ RNA from carrot root tissue, and then translating the RNA in vitro, in the presence of tritiated leucine or proline. A 33-kDa peptide was identified in the translation products as a putative extensin precursor because: (i) it is rich in proline and poor in leucine, and (ii) the message appears to be more abundant when carrot tissue is wounded. From a cDNA library constructed with poly(A)+ RNA from wounded carrots, one cDNA clone (pDC5) was identified that specifically hybridized to poly(A)+ RNA encoding this 33-kDa peptide. We isolated three cDNA clones (pDC11, pDC12, and pDC16) from another cDNA library using pDC5 as a probe. DNA sequence data, RNA hybridization analysis, and hybrid released in vitro translation indicate that the cDNA clone pDC11 encodes extensin and that cDNA clones pDC12 and pDC16 encode the 33-kDa peptide, which as yet has an unknown identity and function. The assumption that the 33-kDa peptide was an extensin precursor was invalid. RNA hybridization and DNA sequence analysis indicate that pDC5 is a hybrid clone corresponding to two RNA species. RNA hybridization analysis showed that RNA encoded by both clone types is accumulated upon wounding.
TL;DR: DNA sequence analysis of NF68 showed 90% homology at the amino acid level compared with the sequence of the porcine 68,000-mol-wt neurofilament protein, and the NF68 probe cross-hybridizes at high stringency with genomic sequences in species as diverse as human, chicken, and (weakly) frog, but not with DNA from Drosophila or sea urchin.
Abstract: A 1.2-kilobase (kb) cDNA clone (NF68) encoding the mouse 68,000-mol-wt neurofilament protein is described. The clone was isolated from a mouse brain cDNA library by low-stringency cross-hybridization with a cDNA probe encoding mouse glial fibrillary acidic protein (Lewis et al., 1984, Proc. Natl. Acad. Sci. USA., 81:2743-2746). The identity of NF68 was established by hybrid selection using mouse brain polyA+ mRNA, and cell-free translation of the selected mRNA species. The cell-free translation product co-migrated with authentic 68,000-mol-wt neurofilament protein on an SDS/polyacrylamide gel, and was immunoprecipitable with a monospecific rabbit anti-bovine neurofilament antiserum. In addition, DNA sequence analysis of NF68 showed 90% homology at the amino acid level compared with the sequence of the porcine 68,000-mol-wt neurofilament protein. At high stringency, NF68 detects a single genomic sequence encoding the mouse 68,000-mol-wt neurofilament protein. Two mRNA species of 2.5 kb and 4.0 kb are transcribed from the single gene in mouse brain. The level of expression of these mRNAs remains almost constant in postnatal mouse brains of all ages and, indeed, in the adult. At reduced stringency, NF68 detects a number of mRNAs that are expressed in mouse brain, one of which encodes the 150,000-mol-wt neurofilament protein. The NF68 probe cross-hybridizes at high stringency with genomic sequences in species as diverse as human, chicken, and (weakly) frog, but not with DNA from Drosophila or sea urchin.
TL;DR: The identification and DNA sequence of a chondroitin sulfate proteoglycan core protein cDNA is reported and the possibility of detecting mRNAs and genomic sequences for other proteoglycans with a serine-glycine repeat by using this cDNA clone is discussed.
Abstract: We report the identification and DNA sequence of a chondroitin sulfate proteoglycan core protein cDNA. A cDNA clone, pPG1, was selected from a rat yolk sac tumor poly(A)+RNA-derived cDNA library by using synthetic oligonucleotides predicted from the NH2-terminal peptide sequence of the mature chondroitin sulfate proteoglycan. The resulting sequence analysis demonstrated that the 874-base-pair pPG1 clone contained the complete coding region of the mature proteoglycan core protein as well as 5' and 3' flanking sequences. The 104 amino acid proteoglycan core protein sequence reveals that the core protein is composed of three regions, the most striking of which is the central 49 amino acid region composed of alternating serine and glycine residues. This region clearly functions as the acceptor site for the attachment of chondroitin sulfate side chains. The serine-glycine repeat region is flanked by a 14 amino acid NH2-terminal region identical to the NH2-terminal sequence of the proteoglycan obtained by amino acid sequencing and a 41 amino acid COOH-terminal region. RNA transfer blot hybridizations of poly(A)+ mRNA from rat yolk sac tumor cells with nick-translated pPG1 reveal a single mRNA of approximately equal to 1300 nucleotides. The possibility of detecting mRNAs and genomic sequences for other proteoglycans with a serine-glycine repeat by using this cDNA clone is discussed.
TL;DR: The nucleotide sequence of the major immediate early (IE) gene of human cytomegalovirus strain AD169 was determined and its protein product is compared with the corresponding IE gene from the Towne strain of HCMV.
TL;DR: Two germinal and 16 somatic reversion events induced by the Enhancer (En) transposable element system at the wx‐8::Spm‐I8 allele of Zea mays were cloned and studied by sequence analysis.
Abstract: Two germinal and 16 somatic reversion events induced by the Enhancer (En) transposable element system at the wx-8::Spm-I8 allele of Zea mays were cloned and studied by sequence analysis. Excision of the Spm-I8 receptor element from the wx gene results in various mutant DNA sequences. This leads to altered gene products, some of which are still capable of restoring the wild-type phenotype. Possible `footprint' sequences that may have arisen by the excision of transposable elements were observed when intron sequences of the wild-type (wx+) and the mutant (wx-m8) alleles of the wx gene were compared. The sequence divergence generated by visitation of a locus by plant transposable elements is discussed with respect to the molecular evolution of new gene functions.