TY - JOUR
T1 - Rem2, a new member of the Rem/Rad/Gem/Kir family of Ras-related GTPases
AU - Finlin, Brian S.
AU - Shao, Haipeng
AU - Kadono-Okuda, Keiko
AU - Guo, Nan
AU - Andres, Douglas A.
PY - 2000/4/1
Y1 - 2000/4/1
N2 - Here we report the molecular cloning and biochemical characterization of Rem2 (for Rem, Rad and Gem-related 2), a novel GTP-binding protein identified on the basis of its homology with the Rem, Rad, Gem and Kir (RGK) family of Ras-related small GTP-binding proteins. Rem2 mRNA was detected in rat brain and kidney, making it the first member of the RGK family to be expressed at relatively high levels in neuronal tissues. Recombinant Rem2 binds GTP saturably and exhibits a low intrinsic rate of GTP hydrolysis. Surprisingly, the guanine nucleotide dissociation constants for both Rem2 and Rem are significantly different than the majority of the Ras-related GTPases, displaying higher dissociation rates for GTP than GDP. Localization studies with green fluorescent protein (GFP)-tagged recombinant protein fusions indicate that Rem2 has a punctate, plasma membrane localization. Deletion of the C-terminal seven amino acid residues that are conserved in all RGK family members did not affect the cellular distribution of the GFP fusion protein, whereas a larger deletion, including much of the polybasic region of the Rem2 C-terminus, resulted in its redistribution to the cytosol. Thus Rem2 is a GTPase of the RGK family with distinctive biochemical properties and possessing a novel cellular localization signal, consistent with its having a unique role in cell physiology.
AB - Here we report the molecular cloning and biochemical characterization of Rem2 (for Rem, Rad and Gem-related 2), a novel GTP-binding protein identified on the basis of its homology with the Rem, Rad, Gem and Kir (RGK) family of Ras-related small GTP-binding proteins. Rem2 mRNA was detected in rat brain and kidney, making it the first member of the RGK family to be expressed at relatively high levels in neuronal tissues. Recombinant Rem2 binds GTP saturably and exhibits a low intrinsic rate of GTP hydrolysis. Surprisingly, the guanine nucleotide dissociation constants for both Rem2 and Rem are significantly different than the majority of the Ras-related GTPases, displaying higher dissociation rates for GTP than GDP. Localization studies with green fluorescent protein (GFP)-tagged recombinant protein fusions indicate that Rem2 has a punctate, plasma membrane localization. Deletion of the C-terminal seven amino acid residues that are conserved in all RGK family members did not affect the cellular distribution of the GFP fusion protein, whereas a larger deletion, including much of the polybasic region of the Rem2 C-terminus, resulted in its redistribution to the cytosol. Thus Rem2 is a GTPase of the RGK family with distinctive biochemical properties and possessing a novel cellular localization signal, consistent with its having a unique role in cell physiology.
KW - GTP
KW - GTP-binding proteins
KW - Signal transduction
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U2 - 10.1042/0264-6021:3470223
DO - 10.1042/0264-6021:3470223
M3 - Article
C2 - 10727423
AN - SCOPUS:0034177553
SN - 0264-6021
VL - 347
SP - 223
EP - 231
JO - Biochemical Journal
JF - Biochemical Journal
IS - 1
ER -