Showing papers by "Cold Spring Harbor Laboratory published in 1977"
TL;DR: Findings imply a new mechanism for the biosynthesis of Ad2 mRNA in mammalian cells which is complementary to sequences within the Ad2 genome which are remote from the DNA from which the main coding sequence of each mRNA is transcribed.
1,091 citations
TL;DR: If the tracks of many cells are examined, cell line characteristic track patterns become apparent and second or third generation descendents of 3T3 cells were observed to repeat track patterns of their ancestor cell.
441 citations
TL;DR: Using electron microscopic RNA loop mapping to determine, to within 200 nucleotides, the chromosome coordinates of the 5′ and 3′ ends of adenovirus type 2 transcripts isolated from the cytoplasm of productively infected human KB cells, the most frequent late RNA loop occurred between coordinates 51.9 and 62.8.
275 citations
TL;DR: Observations suggest that both mRNAs contain a long common sequence, complementary to at least two different sites on the Ad2 genome remote from the start of these two genes.
245 citations
TL;DR: The high sensitivity of this technique, achieved through the use of 32P-labeled RNA of high specific activity, has led to the observation that hybridization of Ad2+ND1 RNA occurs at several locations on the Ad2 genome, in addition to the expected sites of hybridization proximal to the SV40 insertion.
224 citations
TL;DR: Mouse L cells lacking the enzyme thymidine kinase (LMTK-) have been converted to a TK+ phenotype by infection with fragmented HSV2 strain 333 DNA, and it is possible to assign a map location to the TK gene on the HSV genome.
169 citations
TL;DR: It seems possible that the primary cilium has a role in the directional control of a migrating 3T3 cell, and that the main actin containing bundles act as substrate-attached rails along which the nucleus and bulk cytoplasm slide during displacement of the cells.
167 citations
TL;DR: Cell surface alterations during myogenesis have been investigated in Yaffe's myogenic cell line L8, using indirect immunofluorescence with an antibody against the large external transformation-sensitive (LETS) protein.
147 citations
TL;DR: The large, external, transformation-sensitive (LETS) protein is detected on the surface of epithelial cells, whereas fibroblasts build a massive network of fibrillar LETS protein in one-week-old confluent culture, epithelial Cells do not.
131 citations
TL;DR: This series of adenovirus-transformed cell lines exhibits an oncogeni spectrum ranging from being tumorigenic in immunocompetent rats through to nontumorigenicIn adult nude mice, the relevance of the in vitro findings to growth potential in vivo is discussed.
130 citations
TL;DR: It is suggested that the actin-bundle pattern, the angle of the angle, major directional changes during interphase, and the time of the next mitosis are predetermined by the parental cell.
Abstract: Using a new technique to visualize the tracks of moving 3T3 cells and combining it with the visualization of actin-containing microfilament bundles by indirect immunofluorescence (Lazarides, E. and K. Weber. 1974, Proc. Natl. Acad. Sci. U.S.A. 71:2268-2272), I present experiments which suggest that: (a) 30-40% of the pairs of daughter 3T3 mouse fibroblasts in noncloned cultures have mirror symmetrical actin-bundle patterns. (b) The angle between separating daughter cells is approx. 90 degrees or 180 degrees and seems related to the directions of certain actin-containing bundles. (c) Approximately 40% of separately moving daughter cells which did not collide with any other cell in the culture performed directional changes in a mirror symmetrical way. Both daughter cells entered the next mitosis at approximately the same time. I suggest that the actin-bundle pattern, the angle of separation, major directional changes during interphase, and the time of the next mitosis are predetermined by the parental cell.
TL;DR: It appears that epidermal growth factor can control the expression of LETS protein.
Abstract: When the serum concentration of the culture medium is below 0.7 per-cent, 3T3 mouse cells lose most of their large external transformation sensitive (LETS) protein at the cell surface, Subsequent addition of epidermal growth factor results in the reappearance of massive fibrillar LETS protein networks on the surface of conluent 3T3 cells. Thirteen other hormones tested do not have this effect. It appears that epidermal growth factor can control the expression of LETS protein.
TL;DR: Oligonucleotides containing the 5' termini of adenovirus 2 mRNA are selectively retained on columns of dihydroxyboryl cellulose, which was unexpected and its significance is discussed.
TL;DR: Two new sequence-specific endodeoxyribonucleases have been partially purified from Moraxella bovis and each cleave bacteriophage lambda DNA and adenovirus-2 DNA at more than 50 sites.
TL;DR: Cell-free translation of partially purified mRNAs isolated from the cytoplasm of human cells at late times after infection by adenovirus type 2 indicates that the genes for the late Ad2 proteins lie within the following intervals on the conventional Ad2 map.
TL;DR: The recognition sequence of BamHI is determined and it is found that it cleaves the two-fold rotationally symmetric sequence at the positions indicated by the arrows generating fragments with cohesive termini.
Abstract: MANY specific endonucleases (restriction endonucleases) have been isolated and recognition sequences have been determined for a number of them1. The isolation of a new specific endonuclease, BamHI, from Bacillus amyloliquefaciens H has recently been described2. We have determined the recognition sequence of BamHI and find that it cleaves the two-fold rotationally symmetric sequence at the positions indicated by the arrows generating fragments with cohesive termini.
TL;DR: It is discovered that the Mu prophage in Escherichia coli strain DK445, a λcIts857 Sam7 lac5: :Mu cI+ dilysogen, contains a 2600 base-pair long insertion of unknown nature, which suggests that the orientation of Mu G DNA may affect the phage viability and that there may be essential functions encoded within the left-hand 1.7 kilobases of the G segment in the lytic orientation.
TL;DR: Two sequence-specific endonucleases, Xma I and Xma II, have been purified from Xanthomonas malvacearum and make cuts in bacteriophage lambda and adenovirus-2 DNA identical with those produced by Sma I.
TL;DR: These results unexpectedly place the gene for a "late" protein within a region of the genome which is transcribed early during infection
TL;DR: It is reported that hyperosmotic neurosecretion is dependent on [Ca]in, and the movement of calcium ions across the presynaptic membrane is governed by the electrochemical gradient, and by the calcium conductance (gCa).
Abstract: Spontaneous liberation of neurotransmitter quanta is strongly affected by the osmotic pressure of the extracellular fluid. Elevation of the osmolarity by 20-30% increases the rate of release from motor nerve endings by more than one order of magnitude. In this respect the neuromuscular junction resembles some other secretory systems. The mechanism of this hyperosmotic neurosecretion is not yet understood; extracellular calcium ions are not directly responsible, since this effect can be produced in their absence. Recently, it has been suggested that the liberation of neurotransmitter is regulated by the intracellular concentration of free calcium ions. We have therefore examined the hypothesis that hyperosmotic neurosecretion originates from an increase in internal calcium concentration ([Ca]in). At the frog neuromuscular synapse however, it is impossible at present to estimate directly free [Ca]in; hence we used an indirect technique, which is based on two assumptions; first, the frequency of the miniature endplate potentials (m.e.p.p.s.) reflects free [Ca]in. Second, the movement of calcium ions across the presynaptic membrane is governed by the electrochemical gradient, and by the calcium conductance (g(Ca)). If hyperosmotic neurosecretion is caused by an increase in [Ca]in, then increasing g(Ca), under reversed electrochemical gradient for the calcium should cause a reduction in the effect of hyperosmotic stress on transmitter release. We report that hyperosmotic neurosecretion is dependent on [Ca]in.
TL;DR: It is shown here that several Ad5 polypeptides can be distinguished from their Ad2 + ND1 counterparts by SDS-polyacrylamide gel electrophoresis and it is shown that the virus-associated RNAs of Ad2 and Ad5 can be separated electrophoretically, permitting rapid and simple determination of the origin of the DNA surrounding position 0.30 in interserotypic recombinants.
TL;DR: Purified sigma polypeptide was found to stimulate the transcription of phage DNA while having little effect on RNA synthesis with the synthetic DNA poly(dA-dT) as template, and the inhibitory effect of delta protein on poly (dA)-dT transcription was strongly dependent on the presence of KC1 in the RNA synthesis reaction mixture.
Abstract: Bacillus subtilis delta protein is a 21500-Mr polypeptide that can be isolated in association with RNA polymerase holoenzyme from uninfected bacteria and with modified forms of RNA polymerase from cells infected with phage SP01 [Pero, J., Nelson, J. and Fox, T. (1975) Proc. Natl Acad. Sci. U.S.A. 72, 1589]. Although no function has been assigned to δ protein in uninfected cells, this host polypeptide enhances the specificity of transcription by phage-modified forms of RNA polymerase that contain SP01-coded regulatory subunits. This report describes the purification of δ and σ proteins from uninfected B. subtilis and examines the comparative effects of these polypeptides on transcription by core RNA polymerase. Purified σ polypeptide was found to stimulate the transcription of phage DNA while having little effect on RNA synthesis with the synthetic DNA poly(dA-dT) as template. In contrast, purified δ protein markedly depressed the transcription of poly(dA-dT) while having little effect on enzyme activity with phage DNA as template. The inhibitory effect of δ protein on poly(dA-dT) transcription was strongly dependent on the presence of KCl in the RNA synthesis reaction mixture.
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TL;DR: A fine structure map of the EcoRI fragment containing the lambda attachment-site region has been constructed and complete cleavage maps of the entire lambda genome have been obtained for endonucleases BglII,BluI,KpnI, SacI,SacII,SalI andXbaI.
Abstract: A fine structure map of theEcoRI fragment containing the lambda attachment-site region has been constructed. 38 different restriction endonucleases have been employed and 170 sites located in this fragment. In addition, sites in adjacent regions have been determined for several enzymes. Complete cleavage maps of the entire lambda genome have been obtained for endonucleasesBglII,BluI,KpnI,SacI,SacII,SalI andXbaI. The strategy employed for mapping included comparison of deletion and substitution mutants, analysis of mixed digests, and detailed analysis of subfragments.
TL;DR: A 1000 base pair left-end Hin dIII fragment of phage Mu DNA was cloned in the Eco RI cleavage site of plasmid pMB9, using poly(dA·dT) linkers added with terminal transferase to confer a high level of Mu immunity on their hosts.
TL;DR: DNA that contains inverted duplications separated by non-inverted sequences often can form characteristic “underwound loops” when it is denatured and reannealed, used to identify a short inverted duplication flanking the γδ recombination sequence of Escherichia coli F factor and to study DNA from phages Mu and P1 in which the G segments are flanked by inverted duplication.
TL;DR: A restriction-like endonuelease, XbaI, has been partially purified from Xanthomonas badrii and recognizes the sequence and cuts at the sites indicated by the arrows.
TL;DR: A new restriction-like endonuclease, Bal I, has been partially purified from Brevibacterium albidum and cleaves bacteriophage λ DNA at at least 18 times and adenovirus-2 DNA at least 16 times, but does not cleave simian virus 40 DNA.
TL;DR: A link between a motility phenomenon in animal cells and the presence of the so-called ‘large external transformation-sensitive (LETS)’ protein on the surface of the cells is established.
Abstract: WE try here to establish a link between a motility phenomenon in animal cells and the presence of the so-called ‘large external transformation-sensitive (LETS)’ protein on the surface of the cells. Through studies of this protein a new and still puzzling aspect of animal cell surfaces became apparent. Originally discovered as a major surface glycoprotein of molecular weight 220,000–250,000 which disappeared on cell transformation (for review, see ref. 1), it has since become quite likely that various differently named surface glycoproteins—galactoprotein a (ref. 2), fibroblast surface antigen3, Zeta protein4, ‘cell-surface protein’ (CSP)5, and ‘cold-insoluble globulin’ (CIG)6–8—which were studied independently by different investigators, are identical to or at least very closely related to LETS protein.