A novel human BTB-kelch protein KLHL31, strongly expressed in muscle and heart, inhibits transcriptional activities of TRE and SRE.

摘要: The Bric-a-brac, Tramtrack, Broad-complex (BTB) domain is a protein-protein interaction that found in many zinc finger transcription factors. BTB containing proteins play important roles variety of cellular functions including regulation transcription, the cytoskeleton, protein ubiquitination, angiogenesis, and apoptosis. Here, we report cloning characterization novel human gene, hieiPN, from embryonic heart cDNA library. hieiPN 5743 bp long, encoding product 634 amino acids domain. highly conserved across different species. Western blot analysis indicates KLHL31 abundantly expressed both skeletal tissue. In COS-7 cells, are localized to nu-cleus cytoplasm. primary cultures nascent mouse cardiomyocytes, majority endogenous acts as repressor when fused GAL4 DNA-binding deletion main region responsible for this repression. Overex-pression cells inhibits transcriptional activities TPA-response element (TRE) serum response (SRE). also significantly reduces JNK activation leading decreased phosphorylation levels target c-Jun Hela cells. These results suggest may act new MAPK/JNK signaling path-way regulate functions. INTRODUCTION or POZ (Poxvirus finger) was originally identified motif present aececeUaa~=aEa~acO~eiEe Tramtrack (Ttk) Broad Complex (BR-C) (Couderc et al., 2002; Zollman 1994). most proteins, module able self-associate interact with non-BTB (Geyer al K, 2003). This evolutionarily often at NH2-terminus developmentally regulated zinc-finger factors, well some actin associated bearing kelch motif. an ancient evolutionarily-widespread sequence 44-56 acids. It occurs groups five seven repeats has been pro-teins otherwise distinct molecular architecture, termed kelch-repeat superfamily (Prag Recently, BACK (BTB COOH-terminal kelch) de-scribed several BTB-kelch however, its function unknown (Stogios 2004). domain, increasing number poxvirus, `~EaceJU~ACaiae=EaEO~ae , wEAe~NaeU, humans. generally NH