Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 1995 Mar 28;92(7):2974-8.
doi: 10.1073/pnas.92.7.2974.

A single residue can modify target-binding affinity and activity of the functional domain of the Rho-subfamily GDP dissociation inhibitors

J V Platko  1 , D A Leonard, C N Adra, R J Shaw, R A Cerione, B Lim
Affiliations
Comparative Study

A single residue can modify target-binding affinity and activity of the functional domain of the Rho-subfamily GDP dissociation inhibitors

J V Platko et al. Proc Natl Acad Sci U S A. .

Abstract

The GDP dissociation inhibitors (GDIs) represent an important class of regulatory proteins for the Rho- and Rab-subtype GTP-binding proteins. As a first step toward identifying the key functional domain(s) on the Rho-subtype GDI, truncations of the amino and carboxyl termini were performed. Deletion of the final four amino acids from the carboxyl terminus of Rho GDI or the removal of 25 amino acids from the amino terminus had no significant effect on the ability of the GDI to inhibit GDP dissociation from the Rho-like protein Cdc42Hs or on its ability to release Cdc42Hs from membrane bilayers. However, the deletion of 8 amino acids from the carboxyl terminus of Rho GDI eliminated both activities. To further test the importance of the carboxyl-terminal domain of the Rho GDI molecule, chimeras were constructed between this GDI and a related protein designated LD4, which is 67% identical to Rho GDI but is less potent by a factor of 10-20 than Rho GDI in functional assays with the Cdc42Hs protein. Two sets of chimeras were constructed that together indicated that as few as 6 amino acids near the carboxyl terminus of Rho GDI could impart full GDP dissociation inhibition and membrane dissociation activities on the LD4 molecule. Further analysis of this region by site-directed mutagenesis showed that a single change at residue 174 of LD4 to the corresponding residue of Rho GDI (i.e., Asp-174-->Ile) could impart nearly full (70%) Rho GDI activity on the LD4 molecule.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Biochem Biophys Res Commun. 1989 Aug 15;162(3):1438-45 - PubMed
    1. Genes Chromosomes Cancer. 1993 Dec;8(4):253-61 - PubMed
    1. J Biol Chem. 1990 Feb 5;265(4):2333-7 - PubMed
    1. J Biol Chem. 1990 Jun 5;265(16):9373-80 - PubMed
    1. Anal Biochem. 1991 Feb 1;192(2):262-7 - PubMed

Publication types

MeSH terms

Substances