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

CDK2 (cyclin-dependent kinase 2) is a serine/threonine kinase which is involved in regulating S-phase entry in higher eukaryotes. To investigate the transcriptional control of this gene, a 13-kb Xenopus laevis genomic clone containing the 5' flanking sequences was isolated. A 2.7-kb fragment containing the promoter region was sequenced and the transcription start point (tsp) was determined by primer extension. Several putative regulatory elements, such as the E2F-binding site, Y box and octamer-binding site, were localized in this region, but no TATA box was found. When fused to cat, a reporter gene encoding chloramphenicol acetyltransferase, the 5' flanking sequences were shown to function in oocytes and an enhancer activity was found in this region. During early embryogenesis, cdk2 promoter activity was tested and de novo transcription was detected at the mid-blastula transition.
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PMID:Cloning of the Xenopus laevis cdk2 promoter and functional analysis in oocytes and during early development. 782 9

Cytoplasmic poly(A) elongation is one mechanism that regulates translational recruitment of maternal mRNA in early development. In Xenopus laevis, poly(A) elongation is controlled by two cis elements in the 3' untranslated regions of responsive mRNAs: the hexanucleotide AAUAAA and a U-rich structure with the general sequence UUUUUAAU, which is referred to as the cytoplasmic polyadenylation element (CPE). B4 RNA, which contains these sequences, is polyadenylated during oocyte maturation and maintains a poly(A) tail in early embryos. However, cdk2 RNA, which also contains these sequences, is polyadenylated during maturation but deadenylated after fertilization. This suggests that cis-acting elements in cdk2 RNA signal the removal of the poly(A) tail at this time. By using poly(A) RNA-injected eggs, we showed that two elements which reside 5' of the CPE and 3' of the hexanucleotide act synergistically to promote embryonic deadenylation of this RNA. When an identical RNA lacking a poly(A) tail was injected, these sequences also prevented poly(A) addition. When fused to CAT RNA, the cdk2 3' untranslated region, which contains these elements, as well as the CPE and the hexanucleotide, promoted poly(A) addition and enhanced chloramphenicol acetyltransferase activity during maturation, as well as repression of these events after fertilization. Incubation of fertilized eggs with cycloheximide prevented the embryonic inhibition of cdk2 RNA polyadenylation but did not affect the robust polyadenylation of B4 RNA. This suggests that a maternal mRNA, whose translation occurs only after fertilization, is necessary for the cdk2 deadenylation or inhibition of RNA polyadenylation. This was further suggested when poly(A)+ RNA isolated from two-cell embryos was injected into oocytes that were then allowed to mature. Such oocytes became deficient for cdk2 RNA polyadenylation but remained proficient for B4 RNA polyadenylation. These data show that CPE function is developmentally regulated by multiple sequences and factors.
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PMID:Multiple sequence elements and a maternal mRNA product control cdk2 RNA polyadenylation and translation during early Xenopus development. 806 20

Butyrolactone I is a selective inhibitor of the cyclin-dependent kinase (cdk) family, cdk2 and cdc2 kinase. In the present study, the effect of butyrolactone I on expression of the albumin and alpha-fetoprotein (AFP) genes was investigated in HuH-7 human hepatoma cells. Butyrolactone I inhibited cell growth and arrested cells predominantly in G2/M phase. By Northern blot analysis, the levels of both albumin and AFP mRNA were suppressed dose-dependently by butyrolactone I. In transient chloramphenicol acetyltransferase plasmid transfection experiments, the albumin promoter activity and the AFP promoter and enhancer activities were suppressed by butyrolactone I. Consistent with this, the transcripts of hepatocyte nuclear factor-1 (HNF-1), a liver-specific transcription factor which transactivates these promoter and enhancer regions were reduced by butyrolactone I in a dose-dependent manner. These results indicate that butyrolactone I down-regulates both the albumin and the AFP gene transcription through the reduction of HNF-1 expression.
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PMID:Suppression of albumin and alpha-fetoprotein gene expression by butyrolactone I, a selective inhibitor of the cdk family, in HuH-7 human hepatoma cells. 989 85