Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pregnancy-specific glycoproteins (PSGs) of the human placenta and the carcinoembryonic antigens comprise a subfamily within the immunoglobulin superfamily. There may be as many as 20 different PSG genes which are predominantly expressed in the placenta. As an initial step toward understanding the control of PSG expression, we isolated and characterized two nearly identical PSG genes, PSG1 and PSG1-I. PSG1, which lacks exon 1 (5'/L), but contains exons 2 (L/N), 3 (A1), 4 (A2), and 5 (B2-C), encodes five previously identified type I transcripts, PSG1a, 1b, 1c, 1d, and 1e in a L/N-A1-A2-B2-C domain arrangement. PSG1-I, which contains a complete transcriptional unit consisting of exons 5'/L, L/N, A1, and B2-C, encodes type II PSG transcripts in a L/N-A1-B2-C domain arrangement. The predicted PSG1-I-encoded proteins share nearly complete sequence identity with the PSG1-encoded members, except the latter contain extra A domains. Amplification by polymerase chain reaction of placental or hydatidiform mole cDNA demonstrates that PSG1-I is a functional type II PSG gene. Using transient expression assays, we demonstrated that the -834/-34 region upstream of the translational start site of the PSG1-I gene contained the PSG promoter elements and the -834 to -456 region contained negative control elements. Sodium butyrate, an inducer of PSG synthesis, greatly stimulated expression of all PSG1-I-chloramphenicol acetyltransferase (CAT) fusion gene constructs. However, butyrate was at least 2-fold more effective in stimulating CAT activity of fusion genes containing upstream sequences (-834 to -576) than those containing proximal sequences (-456 to -172), suggesting two regions in the PSG1-I gene that mediate the butyrate response.
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PMID:Cloning and expression of genes encoding human pregnancy-specific glycoproteins. 164 21

The pregnancy-specific glycoproteins (PSGs) of the placenta, members of the immunoglobulin superfamily, are encoded by multiple linked genes located on chromosome 19. To study the control of PSG expression, we have immortalized differentiated human placental cells (HP-A1) temperature-sensitive for transformation by a recombinant adenovirus-(ori-)-SV40 tsA mutant virus. We now show that expression of the PSG gene in HP-A1 cells is temperature-sensitive. At the permissive temperature (33 degrees C), these cells expressed low levels of PSG mRNA and synthesized a 64-kDa PSG. Shifting HP-A1 cells to a nonpermissive temperature (39.5 degrees C) increased PSG mRNA expression and biosynthesis with preferential increase in the synthesis of a 54-kDa and a low level of a 72-kDa PSG. Moreover, PSG expression was greatly induced by 5-bromo-2'-deoxyuridine (BudR), which selectively increased synthesis of PSGs of 72 and 54 kDa. In the presence of BudR, HP-A1 synthesized PSGs of 72, 64, and 54 kDa, similar to the pattern seen with placental PSGs. Ribonuclease protection assays demonstrated that HP-A1 cells express the majority of PSG mRNAs and BudR stimulated expression of PSG1 and PSG1-like transcripts. Reverse transcription and polymerase chain reaction analysis using PSG gene-specific primers demonstrated that untreated HP-A1 cells expressed primarily PSG1, PSG2, PSG4, and PSG5 mRNAs. BudR stimulated the expression of all PSG transcripts except PSG4. Moreover, in transient expression assays, BudR increased chloramphenicol acetyltransferase (CAT) expression directed by PSG1-I, PSG4, PSG5, PSG6, and PSG11 promoter-CAT fusion genes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pregnancy-specific glycoprotein gene expression and the induction by 5-bromo-2'-deoxyuridine. 800 89