SIGNAL TRANSDUCTION AND CYTOSKELTON

点击翻译按钮获取中文摘要

The adenylyl cyclase - associated protein, CAP,was first identified in Saccharomyces cerevisiae, and succeedingly, its homologs were found in many eukaryotes ranging from yeasts to humans. Yeast CAPs have been found to have three functions : the N - terminal domain as the region for binding adenylyl cyclase, the C - terminal domain as an actin binding domain, and the central proline - rich domainas the SH3 (Src Homology 3) binding region. Here, we report the identification of a cDNA and genomic DNA encoding a CAP homolog from mushroom Lentinus edodes. Southern blotting results suggest it to be a single - copy gene. The L.edodes cap gene contains 8 introns and an open reading frame encoding a 518 amino acid protein. The C - terminal domain shares higher homology (39 - 46 % identity) compared with the N - terminal domain (27 - 35 % identity) with yeast CAPs. Expression of the L.edodes CAP in both S.pombe and in S.cerevisiae complemented defects associated with loss of the C - terminal domain function of endogenous CAP.By using yeast two - hybrid assay, we demonstrated the interaction between the L.edodes CAP and S.pombe actin. This result andfunctional complementation test indicate CAP from mushroom is conserved in terms of the C - terminal function of CAP.