TY - JOUR
T1 - p140Sra-1 (specifically Rac1-associated protein) is a novel specific target for Rac1 small GTPase
AU - Kobayashi, Kenta
AU - Kuroda, Shinya
AU - Fukata, Masaki
AU - Nakamura, Tomoko
AU - Nagase, Takahiro
AU - Nomura, Nobuo
AU - Matsuura, Yoshiharu
AU - Yoshida-Kubomura, Nobuko
AU - Iwamatsu, Akihiro
AU - Kaibuchi, Kozo
PY - 1998/1/2
Y1 - 1998/1/2
N2 - Rac1 small GTPase plays pivotal roles in various cell functions such as cell morphology, cell polarity, and cell proliferation. We have previously identified IQGAP1 from bovine brain cytosol as a target for Rac1 by an affinity purification method. By using the same method, we purified a specifically Rac1-associated protein with a molecular mass of about 140 kDa (p140) from bovine brain cytosol. This protein interacted with guanosine 5'- (3-O-thio)triphosphate (GTPγS)-glutathione S-transferase (GST)-Rac1 but not with the GDP·GST-Rac1, GTPγS·GST-Cdc42, or GTPγS·GST-RhoA. The amino acid sequences of this protein revealed that p140 is identified as a product of KIAA0068 gene. We denoted this protein as Sra-1 (Specifically Rac1- associated protein). Recombinant Sra-1 interacted with GTPγS·GST-Rac1 and weakly with GDP·Rac1 but not with GST-Cdc42 or GST-RhoA. The N-terminal domain of Sra-1 (1-407 amino acids) was responsible for the interaction with Rac1. Myc-tagged Sra-1 and the deletion mutant capable of interacting with Rac1, but not the mutants unable to bind Rac1, were colocalized with dominant active Rac1(Val-12) and cortical actin filament at the Rac1(Val-12), induced membrane ruffling area in KB cells. Sra-1 was cosedimented with filamentous actin (F-actin), indicating that Sra-1 directly interacts with F-actin. These results suggest that Sra-1 is a novel and specific target for Rac1.
AB - Rac1 small GTPase plays pivotal roles in various cell functions such as cell morphology, cell polarity, and cell proliferation. We have previously identified IQGAP1 from bovine brain cytosol as a target for Rac1 by an affinity purification method. By using the same method, we purified a specifically Rac1-associated protein with a molecular mass of about 140 kDa (p140) from bovine brain cytosol. This protein interacted with guanosine 5'- (3-O-thio)triphosphate (GTPγS)-glutathione S-transferase (GST)-Rac1 but not with the GDP·GST-Rac1, GTPγS·GST-Cdc42, or GTPγS·GST-RhoA. The amino acid sequences of this protein revealed that p140 is identified as a product of KIAA0068 gene. We denoted this protein as Sra-1 (Specifically Rac1- associated protein). Recombinant Sra-1 interacted with GTPγS·GST-Rac1 and weakly with GDP·Rac1 but not with GST-Cdc42 or GST-RhoA. The N-terminal domain of Sra-1 (1-407 amino acids) was responsible for the interaction with Rac1. Myc-tagged Sra-1 and the deletion mutant capable of interacting with Rac1, but not the mutants unable to bind Rac1, were colocalized with dominant active Rac1(Val-12) and cortical actin filament at the Rac1(Val-12), induced membrane ruffling area in KB cells. Sra-1 was cosedimented with filamentous actin (F-actin), indicating that Sra-1 directly interacts with F-actin. These results suggest that Sra-1 is a novel and specific target for Rac1.
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U2 - 10.1074/jbc.273.1.291
DO - 10.1074/jbc.273.1.291
M3 - Article
C2 - 9417078
AN - SCOPUS:0031972690
SN - 0021-9258
VL - 273
SP - 291
EP - 295
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -