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Biomedical subjects

R C Pillutla

Publications and source records attributed to R C Pillutla.

6 recordsLinked to original sources

A surrogate-based approach for post-genomic partner identification.

BACKGROUND: Modern drug discovery is concerned with identification and validation of novel protein targets from among the 30,000 genes or more postulated to be present in the human genome. While protein-protein interactions may be central to many disease indications, it has been difficult to identify new chemical entities capable of regulating these interactions as either agonists or antagonists. RESULTS: In this paper, we show that peptide complements (or surrogates) derived from highly diverse random phage display libraries can be used for the identification of the expected natural biological partners for protein and non-protein targets. Our examples include surrogates isolated against both an extracellular secreted protein (TNFbeta) and intracellular disease related mRNAs. In each case, surrogates binding to these targets were obtained and found to contain partner information embedded in their amino acid sequences. Furthermore, this information was able to identify the correct biological partners from large human genome databases by rapid and integrated computer based searches. CONCLUSIONS: Modified versions of these surrogates should provide agents capable of modifying the activity of these targets and enable one to study their involvement in specific biological processes as a means of target validation for downstream drug discovery.

Computational Biology↗

Genomic structure and chromosomal localization of TCEAL1, a human gene encoding the nuclear phosphoprotein p21/SIIR.

Human p21/SIIR is a novel Ser/Arg/Pro-rich nuclear phosphoprotein that is 48% similar to transcription factor SII and modulates transcription in a promoter context-dependent fashion. We have obtained the complete sequence of TCEAL1, the gene that codes for p21/SIIR. This gene consists of three exons and two introns with the entire coding sequence in exon III. Tissue-specific expression patterns of TCEAL1 by Northern blot analysis showed the presence of an approximately 1.2-kb transcript in all normal human tissues examined, and heart and skeletal muscle contained an additional transcript of approximately 7 kb. Expression was lowest in hematopoietic cells of both normal and tumor origin. TCEAL1 was mapped to human chromosome Xq22.1 by fluorescence in situ hybridization.

Animals↗

Recombinant human mRNA cap methyltransferase binds capping enzyme/RNA polymerase IIo complexes.

Guanine N-7 methylation is an essential step in the formation of the m7GpppN cap structure that is characteristic of eukaryotic mRNA 5' ends. The terminal 7-methylguanosine is recognized by cap-binding proteins that facilitate key events in gene expression including mRNA processing, transport, and translation. Here we describe the cloning, primary structure, and properties of human RNA (guanine-7-)methyltransferase. Sequence alignment of the 476-amino acid human protein with the corresponding yeast ABD1 enzyme demonstrated the presence of several conserved motifs known to be required for methyltransferase activity. We also identified a Drosophila open reading frame that encodes a putative RNA (guanine-7-)methyltransferase and contains these motifs. Recombinant human methyltransferase transferred a methyl group from S-adenosylmethionine to GpppG 5'ends, which are formed on RNA polymerase II transcripts by the sequential action of RNA 5'-triphosphatase and guanylyltransferase activities in the bifunctional mammalian capping enzyme. Binding studies demonstrated that the human cap methyltransferase associated with recombinant capping enzyme. Consistent with selective capping of RNA polymerase II transcripts, methyltransferase also formed ternary complexes with capping enzyme and the elongating form of RNA polymerase II.

Amino Acid Sequence↗

Deletion of the putative effector region of Era, an essential GTP-binding protein in Escherichia coli, causes a dominant-negative phenotype.

Era is an essential gene in E. coli, encoding a GTP-binding protein of unknown function. In the present work, a mutant designated Era-dE, for deletion of effector region is described. This is the first and only known era allele that confers a dominant-negative phenotype. Phenotypic analysis of the mutant showed that overproduction of Era-dE caused a dominant inhibition of growth when TCA cycle intermediates such as succinate, pyruvate, malate, alpha-ketoglutarate, and fumarate were provided as the sole carbon source. Examination of the macromolecular composition of cells overexpressing the mutant showed protein, DNA, and ATP levels expected for cells growing at slow rates. The response of cells expressing Era-dE to different stress conditions was studied by examining the rates of synthesis of stress-inducible proteins. Interestingly, when subjected to succinate starvation, cells expressing Era-dE showed a defective carbon starvation response, whereas response to glucose starvation was similar to that seen in control cells. Taken together with previous results, these studies indicate that Era is perhaps involved in multiple cellular processes and Era-dE disrupts more than one of these functions. Furthermore, it appears that some possible functions of Era include regulation of the TCA cycle and response to carbon starvation.

Adenosine Triphosphate↗

Cross-species complementation of the indispensable Escherichia coli era gene highlights amino acid regions essential for activity.

Era is an essential GTP binding protein in Escherichia coli. Two homologs of this protein, Sgp from Streptococcus mutans and Era from Coxiella burnetii, can substitute for the essential function of Era in E. coli. Site-specific and randomly generated Era mutants which may indicate regions of the protein that are of functional importance are described.

Amino Acid Sequence↗