Biomedical subjects

C T Powell

Publications and source records attributed to C T Powell.

23 records · Page 2Linked to original sources

PubMed1993

Molecular cloning of a complementary DNA encoding a prostate-specific membrane antigen.

Recently, a novel M(r) 100,000 prostate-specific membrane glycoprotein (PSM) has been detected by the prostate-specific monoclonal antibody 7E11-C5, raised against the human prostatic carcinoma cell line LNCaP. The PSM antigen is expressed exclusively by normal and neoplastic prostate cells and metastases. We now report the molecular cloning of a full-length 2.65-kilobase complementary DNA encoding the PSM antigen from a human LNCaP complementary DNA library by polymerase chain reaction using degenerate oligonucleotide primers. Analysis of the complementary DNA sequence has revealed that a portion of the coding region, from nucleotide 1250 to 1700, has 54% homology to the human transferrin receptor mRNA. The deduced polypeptide has a putative transmembrane domain enabling the delineation of intra- and extracellular portions of this antigen. In contrast to prostate-specific antigen and prostatic acid phosphatase which are secreted proteins, PSM as an integral membrane protein may prove to be effective as a target for imaging and cytotoxic targeting modalities.

Amino Acid Sequence↗

PubMed1992

Cloning of a D-type cyclin from murine erythroleukemia cells.

We report the complete coding sequence of a cDNA, designated CYL2, derived from a murine erythroleukemia cell library. CYL2 is considered to encode a D-type cyclin because (i) there is cross hybridization with CYL1 (a murine homolog of human cyclin D1) and the encoded protein has 64% amino acid sequence identity with CYL1 and (ii) murine erythroleukemia cell-derived CYL2 contains an amino acid sequence identical to that previously reported for the C-terminal portion of a partially sequenced CYL2. Transcripts of murine erythroleukemia cell CYL2 undergo alternative polyadenylylation like that of human cyclin D1. A major 6.5-kilobase CYL2 transcript changes its expression during the cell cycle with a broad peak through G1 and S phases and a decrease in G2/M phases. The present findings suggest that CYL2 plays a role in the G1 to S phase progression.

Amino Acid Sequence↗

PubMed1992

Protein kinase C isozymes epsilon and alpha in murine erythroleukemia cells.

Protein kinase C (PKC) has a role in signal transduction during hexamethylene bisacetamide (HMBA)-induced differentiation of murine erythroleukemia cells (MELC). Separation of MELC PKC isozymes by hydroxylapatite chromatography yields a major peak (III) and a minor peak (II) of PKC activity, previously reported to contain the PKC alpha and beta isozymes, respectively. In the present study, we confirm that peak III activity is PKC alpha but show that peak II contains PKC epsilon and little or no PKC beta. Immunoblot analysis with isozyme-specific anti-alpha and anti-epsilon PKC antibodies detected PKC alpha in peak III and PKC epsilon in peak II. Peak III activity was markedly enhanced (up to 20-fold) by phosphatidylserine, diolein, and Ca2+, whereas addition of these cofactors to the reaction mixture stimulated peak II activity only 2- to 4-fold. RNase protection analysis of MELC RNA showed that PKC alpha and PKC epsilon RNAs were in a ratio of approximately 2:1, but PKC beta RNA was barely detectable. Taken together, these data indicate that MELC contain PKC alpha and PKC epsilon but little or no PKC beta.

Animals↗

PubMed1985

A gastrin gene is expressed in both porcine pituitary and antral mucosal tissues.

By employing S1 nuclease mapping of total RNA isolated from porcine cerebral cortex, cerebellum, hypothalamus, pituitary, kidney, liver, pancreas, intestine, and antral mucosa, we have investigated gastrin gene expression in these tissues. Our results show that a gastrin gene is expressed only in the antral mucosal and pituitary tissues. Based on the amount of gastrin specific probe protected from S1 nuclease digestion in the presence of a given weight of total RNA, the amount of gastrin mRNA present in pituitary is approximately 330 times lower than in antral mucosa. These findings help establish the tissue distribution of gastrin gene expression.

Animals↗

PubMed1982

Molecular cloning and nucleotide sequence of full-length of cDNA coding for porcine gastrin.

We have cloned in EScherichia coli a cDNA copy of mRNA coding for the porcine antral mucosal hormone preprogastrin. Full-length double-stranded cDNA was synthesized and inserted into the Pst I endonuclease site in plasmid pBR322 by using a homopolymeric extension technique. A partial cDNA clone was used as a probe to identify a complete cDNA clone in a cDNA library by colony hybridization. Four positive clones were isolated, one of which corresponded to porcine preprogastrin mRNA. The nucleotide sequence of the cDNA insert (602 nucleotides) revealed 312 nucleotides in the entire mRNA coding region, 61 nucleotides in the 5' untranslated region, 86 nucleotides in the 3'untranslated region, and a poly(A) tail of 86 nucleotides. Gastrin is located near the carboxyl end of preprogastrin and is flanked at both its amino and carboxyl ends by a pair of basic amino acid residues. The presence of glycine and a pair of basic amino acid residues adjacent in the carboxyl-terminal phenylalanine of gastrin indicates that the glycine and a pair of basic amino acid residues may be required for the enzymatic amidation of phenylalanine to phenylalanine amide.

Animals↗