Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 277, Issue 20, Pages 17385-17388Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.c100620200
Keywords
-
Categories
Funding
- NIGMS NIH HHS [GM-50526] Funding Source: Medline
Ask authors/readers for more resources
Ran-binding protein 3 (RanBP3) is an similar to55-kDa protein that functions as a cofactor for Crm1-mediated nuclear export. RanBP3 stimulates export by enhancing the affinity of Crm1 for Ran-GTP and cargo. However, important additional functions for this cofactor may exist. We now report that RanBP3 associates with the Ran-specific guanine nucleotide exchange factor, regulator of chromosome condensation 1 (RCC1). This interaction was stimulated by the addition of Ran; moreover, Ran.GDP, Ran.TP, and Ran without nucleotide could all stimulate complex formation between RanBP3 and RCC1 even though binding of Ran.GDP to RanBP3 alone was undetectable. RanBP3 could also promote binding of Crm1 to RCC1 in the presence of Ran. Binding of RanBP3 to RCC1 increased the catalytic activity of RCC1 toward Ran, and importantly, the ability of RanBP3 to stimulate RCC1 was not affected by the presence of Crm1. These data indicate that RanBP3 acts as a scaffold protein to promote the efficient assembly of export complexes. By tethering Crm1 to catalytically enhanced RCC1, RanBP3 may lower the entropic barrier for the loading of Ran.GTP onto Crm1. We propose that this provides an additional mechanism by which RanBP3 facilitates export.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available