TRIM45, a novel human RBCC/TRIM protein, inhibits transcriptional activities of ElK-1 and AP-1.
The tripartite motif (TRIM) proteins play important roles in a variety of cellular functions including cell proliferation, differentiation, development, oncogenesis, and apoptosis. In this study, we report the identification and characterization of the human tripartite motif-containing protein 45 (TRIM45), a novel member of the TRIM family, from a human embryonic heart cDNA library. TRIM45 has a predicted 580 amino acid open reading frame, encoding a putative 64-kDa protein. The N-terminal region harbors a RING finger, two B-boxes, and a predicted alpha-helical coiled-coil domain, which together form the RBCC/TRIM motif found in a large family of proteins, whereas the C-terminal region contains a filamin-type immunoglobulin (IG-FLMN) domain. Northern blot analysis indicates that TRIM45 is expressed in a variety of human adult and embryonic tissues. In the cell, TRIM45 protein is expressed both in cytoplasm and in cell nucleus. Overexpression of TRIM45 in COS-7 cells inhibits the transcriptional activities of ElK-1 and AP-1. These results suggest that TRIM45 may act as a new transcriptional repressor in mitogen-activated protein kinase signaling pathway.
Wang
Yuequn
Y
The Center for Heart Development, College of Life Sciences, Hunan Normal University, Changsha 410081, Hunan, People's Republic of China.
Li
Yongqing
Y
Qi
Xinzhu
X
Yuan
Wuzhou
W
Ai
Jianping
J
Zhu
Chuanbing
C
Cao
Lei
L
Yang
Hong
H
Liu
Fang
F
Wu
Xiushan
X
Liu
Mingyao
M
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D015152:Blotting, Northern; D019556:COS Cells; D002454:Cell Differentiation; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D019295:Computational Biology; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005091:Exons; D015723:Gene Library; D017930:Genes, Reporter; D006801:Humans; D020935:MAP Kinase Signaling System; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D016366:Open Reading Frames; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012313:RNA / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014018:Tissue Distribution; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D050807:ets-Domain Protein Elk-1
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C493156:TRIM45 protein, human; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D012313:RNA