A putative effector of Ral has homology to Rho/Rac GTPase activating proteins.
We report here the cloning of a gene encoding a novel Ral interacting protein (RIP1) from a cDNA expression library using radiolabeled Ral as probe. RIP1 binds to Ral in a GTP-dependent manner. The 4.1 kb transcript of the RIP1 gene is present in all tissues analysed and encodes for a protein product of 648 residues. RIP1 shares sequence similarity with GAP proteins that are capable of activating the GTPase activity of members of the Rho/Rac family of GTPases. When tested, RIP1 could activate the GTPase activity of CDC42 and, to a lesser extent, Rac1 but not RhoA, Ras, or Ral. Activated Ral had no effect on the GTPase-activating ability of RIP1, in vitro.
Park
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SH
Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge 02142, USA.
Weinberg
R A
RA
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D020690:GTPase-Activating Proteins; D006150:Guanine Nucleotides / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020703:ras GTPase-Activating Proteins
D020690:GTPase-Activating Proteins; D006150:Guanine Nucleotides; D011506:Proteins; C490620:Ralbp1 protein, mouse; D020703:ras GTPase-Activating Proteins