Author
Phillip A. Sharp
Other affiliations: McGovern Institute for Brain Research, Medical Research Council, California Institute of Technology ...read more
Bio: Phillip A. Sharp is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: RNA & RNA splicing. The author has an hindex of 172, co-authored 614 publications receiving 117126 citations. Previous affiliations of Phillip A. Sharp include McGovern Institute for Brain Research & Medical Research Council.
Topics: RNA, RNA splicing, Gene, Transcription (biology), DNA
Papers published on a yearly basis
Papers
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TL;DR: A general protocol for controlled gene amplification is described, which allows conditional expression of high levels of amber suppressor activity in monkey kidney cells, and its use in the genetic analysis of animal viruses is demonstrated by the generation and propagation of the first nonsense mutant of poliovirus.
86 citations
TL;DR: Interestingly, several attempts to obtain the equivalent virus stock of an SV40 recombinant containing the opal suppressor tRNA gene yielded virus lacking the opAL suppressorTRNA gene, suggesting that expression of an efficient opal suppression derived from a human serine t RNA gene is highly detrimental to either cellular or viral processes.
Abstract: Amber, ochre and opal suppressor tRNA genes have been generated by using oligonucleotide directed site-specific mutagenesis to change one or two nucleotides in a human serine tRNA gene. The amber and ochre suppressor (Su+) tRNA genes are efficiently expressed in CV-1 cells when introduced as part of a SV40 recombinant. The expressed amber and ochre Su+ tRNAs are functional as suppressors as demonstrated by readthrough of the amber codon which terminates the NS1 gene of an influenza virus or the ochre codon which terminates the hexon gene of adenovirus, respectively. Interestingly, several attempts to obtain the equivalent virus stock of an SV40 recombinant containing the opal suppressor tRNA gene yielded virus lacking the opal suppressor tRNA gene. This suggests that expression of an efficient opal suppressor derived from a human serine tRNA gene is highly detrimental to either cellular or viral processes.
86 citations
TL;DR: A model is proposed in which repression of PF4 expression in nonmegakaryocytes is mediated, in part, by competition between GATA-binding proteins and basal factors for the core promoter.
85 citations
TL;DR: The presence of in-phase spacing between adjacent binding sites for this family of proteins in the immunoglobulin heavy-chain enhancer suggests the possible formation of an unusual triple-bended structure and may have implications for the activities of Myc.
Abstract: A distinct family of DNA-binding proteins is characterized by the presence of adjacent "basic," helix-loop-helix, and leucine zipper domains. Members of this family include the Myc oncoproteins, their binding partner Max, and the mammalian transcription factors USF, TFE3, and TFEB. Consistent with their homologous domains, these proteins bind to DNA containing the same core hexanucleotide sequence CACGTG. Analysis of the conformation of DNA in protein-DNA complexes has been undertaken with a circular permutation assay. Large mobility anomalies were detected for all basic/helix-loop-helix/leucine zipper proteins tested, suggesting that each protein induced a similar degree of bending. Phasing analysis revealed that basic/helix-loop-helix/leucine zipper proteins orient the DNA bend toward the minor groove. The presence of in-phase spacing between adjacent binding sites for this family of proteins in the immunoglobulin heavy-chain enhancer suggests the possible formation of an unusual triple-bended structure and may have implications for the activities of Myc.
85 citations
TL;DR: It is suggested that regulation of a promoter by the EIa region does not depend on the presence of a set of specific sequences, but instead reflects a characteristic of promoters that have been exogenously introduced into cells.
Abstract: During adenovirus infection, the EII promoter is positively regulated by products of the EIa region. The authors have studied this regulation by fusing a DNA segment containing the adenovirus EII promoter to a dihydrofolate reductase cDNA segment. Expression of this hybrid gene is stimulated in trans when cell lines containing an integrated copy are either transfected with plasmids carrying the EIa region or infected with adenovirus. This suggests that EIa activity regulates transcription of the EII promoter in the absence of other viral proteins and that this stimulation can occur when the EII promoter is organized in cellular chromatin. Transcription from the EII promoter is initiated at two sites in cell lines lacking EIa activity. Introduction of the EIa region preferentially stimulated transcription from one of these two sites. A sensitive, stable cotransfection assay was used to test for specific EII sequences required for stimulation. EIa activity stimulates all mutaant promoters; the most extensive deletion retained only 18 base pairs of sequences upstream of the initiation site. They suggest that regulation of a promoter by the EIa region does not depend on the presence of a set of specific sequences, but instead reflects a characteristic of promoters that have beenmore » exogenously introduced into cells. Insertion of the 72-base-pair repeat of simian-virus 40 in cis enhances transcription from the EII promoter. The stimulatory effects of EIa activity and of the simian virus 40 sequence are additive and appear to differ mechanistically.« less
85 citations
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TL;DR: Although they escaped notice until relatively recently, miRNAs comprise one of the more abundant classes of gene regulatory molecules in multicellular organisms and likely influence the output of many protein-coding genes.
32,946 citations
TL;DR: The results of an international collaboration to produce and make freely available a draft sequence of the human genome are reported and an initial analysis is presented, describing some of the insights that can be gleaned from the sequence.
Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.
22,269 citations
28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
TL;DR: The current understanding of miRNA target recognition in animals is outlined and the widespread impact of miRNAs on both the expression and evolution of protein-coding genes is discussed.
18,036 citations
TL;DR: In this paper, a procedure for extracting plasmid DNA from bacterial cells is described, which is simple enough to permit the analysis by gel electrophoresis of 100 or more clones per day, yet yields DNA which is pure enough to be digestible by restriction enzymes.
Abstract: A procedure for extracting plasmid DNA from bacterial cells is described. The method is simple enough to permit the analysis by gel electrophoresis of 100 or more clones per day yet yields plasmid DNA which is pure enough to be digestible by restriction enzymes. The principle of the method is selective alkaline denaturation of high molecular weight chromosomal DNA while covalently closed circular DNA remains double-stranded. Adequate pH control is accomplished without using a pH meter. Upon neutralization, chromosomal DNA renatures to form an insoluble clot, leaving plasmid DNA in the supernatant. Large and small plasmid DNAs have been extracted by this method.
13,805 citations