Novel isoforms of human cyclic AMP-responsive element modulator (hCREM) mRNA.
The cyclic AMP-response element (CRE), a transcriptional enhancer, is regulated by CREB (CRE-binding protein) which is the leucine zipper protein phosphorylated by protein kinase A in response to cAMP signal. The highly homologous protein CREM (CRE-modulator) is thought to modulate CREB-stimulated transcription, and is also involved in transcriptional control during spermatogenesis. In this paper, we report two types of cDNAs of human CREM (hCREM), type 1 and type 2; type 1 is a group of human counterparts of the mouse CREM alpha and type 2 is a novel form having a distinct 5' exon which is unrelated to any species of the CREB and CREM isoforms so far described. This unique 5' region of type 2 hCREM may suggest its independent expression from type 1 CREM. The specific 5' region of type 2 hCREM consisted of 88 bp, containing an initiation codon for translation, but no possible phosphorylation site, suggesting different roles from type 1 CREM. Both type 1 and 2 hCREMs are expressed in lymphoid and non-lymphoid cell lines. Their excess expression by transfection induced suppression of cAMP-mediated activation of transcription, suggesting their negative regulation of CRE-mediated transcription.
Fujimoto
T
T
Department of Cellular and Molecular Biology, University of Tokyo.
Fujisawa
J
J
Yoshida
M
M
D051698:Activating Transcription Factor 2; D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D051786:Cyclic AMP Response Element Modulator; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D006367:HeLa Cells; D006801:Humans; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins; D013237:Stereoisomerism; D014157:Transcription Factors; D014158:Transcription, Genetic; D014162:Transfection
D051698:Activating Transcription Factor 2; D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; D051786:Cyclic AMP Response Element Modulator