文章基本信息

标题：Protein kinase A-anchoring (AKAP) domains in brefeldin A-inhibited guanine nucleotide-exchange protein 2 (BIG2)
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作者：Hewang Li ; Ronald Adamik ; Gustavo Pacheco-Rodriguez 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：4
页码：1627-1632
DOI：10.1073/pnas.0337678100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Like other guanine nucleotide-exchange proteins (GEPs) that activate ADP-ribosylation factor (ARF) GTPases, brefeldin A-inhibited GEP2, BIG2, contains an {approx}200-aa Sec7 domain that is responsible for this catalytic activity and its inhibition by brefeldin A. The Sec7 domain is located near the center of the molecule and serves to accelerate replacement of GDP bound to ARF with GTP. To explore possible functions of the N-terminal region of BIG2 (1-832), we used three coding-region constructs as bait to screen a human heart cDNA library in a yeast two-hybrid system, retrieving two unique clones that encode a type I protein kinase A (PKA) regulatory subunit, RI. Coimmunoprecipitation experiments confirmed interaction of in vitro translated BIG2 and RI, as well as of the endogenous proteins in cytosol of cultured HepG2 cells. Using 28 deletion mutants, we found three regions of BIG2 that interacted with R subunits of PKA. Residues 27-48 (domain A) interacted with RI and RI{beta