Partial purification and characterization of GDP dissociation stimulator (GDS) for the rho proteins from bovine brain cytosol

Isomura, Mitsuo; Kaibuchi, Kozo; Yamamoto, Takakazu; Kawamura, Shingo; Katayama, Masaya; Takai, Yoshimi

doi:10.1016/0006-291x(90)90380-6

Cited by 43 publications

(17 citation statements)

References 32 publications

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“…SmgGDS is a eukaryotic GEF composed of entirely armadillo (ARM) repeats that does not belong to either the Dbl or DOCK family (11). Despite its early identification as a GEF (12,13), details of the mechanism by which SmgGDS stimulates nucleotide exchange remain sparse.…”

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confidence: 99%

“…SmgGDS was originally characterized as activating multiple GTPases, including Ras family members Rap1A (14), Rap1B (13), and K-ras (14), as well as the Rho family members Rac1 (15), Rac2 (16), Cdc42 (17), RhoA (12), and RhoB (12). However, early experiments using SmgGDS were performed with crudely purified protein samples (12,13) and yielded inconsistent reports of GTPase specificity.…”

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confidence: 99%

“…However, early experiments using SmgGDS were performed with crudely purified protein samples (12,13) and yielded inconsistent reports of GTPase specificity. In addition, some reports claimed that SmgGDS only activated prenylated small GTPases (14,18) whereas others reported activity independent of prenylation state (16,19).…”

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confidence: 99%

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SmgGDS Is a Guanine Nucleotide Exchange Factor That Specifically Activates RhoA and RhoC

Hamel¹,

Monaghan-Benson²,

Rojas³

et al. 2011

Journal of Biological Chemistry

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SmgGDS is an atypical guanine nucleotide exchange factor (GEF) that promotes both cell proliferation and migration and is up-regulated in several types of cancer. SmgGDS has been previously shown to activate a wide variety of small GTPases, including the Ras family members Rap1a, Rap1b, and K-Ras, as well as the Rho family members Cdc42, Rac1, Rac2, RhoA, and RhoB. In contrast, here we show that SmgGDS exclusively activates RhoA and RhoC among a large panel of purified GTPases. Consistent with the well known properties of GEFs, this activation is catalytic, and SmgGDS preferentially binds to nucleotide-depleted RhoA relative to either GDP-or GTP␥S-bound forms. However, mutational analyses indicate that SmgGDS utilizes a distinct exchange mechanism compared with canonical GEFs and in contrast to known GEFs requires RhoA to retain a polybasic region for activation. A homology model of SmgGDS highlights an electronegative surface patch and a highly conserved binding groove. Mutation of either area ablates the ability of SmgGDS to activate RhoA. Finally, the in vitro specificity of SmgGDS for RhoA and RhoC is retained in cells. Together, these results indicate that SmgGDS is a bona fide GEF that specifically activates RhoA and RhoC through a unique mechanism not used by other Rho family exchange factors.

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SmgGDS Is a Guanine Nucleotide Exchange Factor That Specifically Activates RhoA and RhoC

Hamel¹,

Monaghan-Benson²,

Rojas³

et al. 2011

Journal of Biological Chemistry

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“…The conversion from the GDP-bound inactive form to the GTP-bound active form is regulated by GDP/GTP exchange proteins and the reverse conversion is regulated by GTPase-activating proteins. There are two types of GDP/GTP exchange proteins for Rho; one is a stimulatory type, named Stag GDP dissociation stimulator (GDS) and Rho GDS (Isomura et al, 1990), and the other is an inhibitory type, named Rho GDP dissociation inhibitor (GDI) (Fukumoto et al, 1990). We have recently demonstrated that a protooncogene product, Dbl, acts as a GDS for Rho (Yaku et al, 1994).…”

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confidence: 99%

Growth site localization of Rho1 small GTP-binding protein and its involvement in bud formation in Saccharomyces cerevisiae.

Yamochi

Tanaka

Nonaka

et al. 1994

The Journal of Cell Biology

234

206

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Abstract. The Rho small GTP-binding protein family regulates various actomyosin-dependent cell functions, such as cell morphology, locomotion, cytokinesis, membrane ruffling, and smooth muscle contraction. In the yeast Saccharomyces cerevisiae, there is a homologue of mammalian RhoA, RH01, which is essential for vegetative growth of yeast cells. To explore the function of the RH01 gene, we isolated a recessive temperature-sensitive mutation of Rtt01, rho1-104. The rho1-104 mutation caused amino acid substitutions of Asp 72 to Asn and Cys 164 to Tyr of Rholp. Strains bearing the rho1-104 mutation accumulated tiny-or small-budded cells in which cortical actin patches were clustered to buds at the restrictive temperature. Cell lysis and cell death were also seen with the rho1-104 mutant. Indirect immunofluorescence microscopic study demonstrated that Rholp was concentrated to the periphery of the cells where cortical actin patches were clustered, including the site of bud emergence, the tip of the growing buds, and the motherbud neck region of cells prior to cytokinesis. Indirect immunofluorescence study with cells overexpressing RH01 suggested that the Rholp-binding site was saturable. A mutant Rholp with an amino acid substitution at the lipid modification site remained in the cytoplasm. These results suggest that Rhol small GTP-binding protein binds to a specific site at the growth region of cells, where Rholp exerts its function in controlling cell growth. THE yeast Saccharomyces cerevisiae grows by budding for cell division (Drubin, 1991;Nelson, 1992). This polarized cell growth is initiated by signals from the cell surface that result in realignment of the cytoskeleton and the biosynthetic machinery toward a targeting patch at the bud site. Membrane protein transport to the cell surface is mediated by vesicles, which become selectively targeted to the bud site. Bud site assembly and growth are also coupled to reorganization of the actin cytoskeleton. Disruption of the single actin gene in S. cerevisiae results in abnormal cell growth and intraceUular accumulation of vesicles (Novick and Botstein, 1985). Moreover, there is a strong correlation between occurrence of active growth at the bud tip and clustering of cortical actin patches at the same tip. Cortical actin patches are concentrated at the site of bud emergenceThe present address of W. Yamochi is Department of Internal Medicine (lst Division), Kobe University School of Medicine, Kobe 650, Japan.The present address of K. Tanaka, H. Nonaka, and Y. Takai is Department of Molecular Biology and Biochemistry, Osaka University Medical School, 2-2 Yamada-oka, Suita 565, Japan.The present address of T. Musha is Division of Cardiovascular Pharmacology, Eisai Co., Ltd., 1-3-5 Tokaidai, Tsulmba, Ibaraki 300-26, Japan.Address all correspondence to Y. Takai, Department of Molecular Biology and Biochemistry, Osaka University Medical School, 2-2 Yamada-oka, Suita 565, Japan.on unbudded cells and in small and medium size buds in budding cells, whereas actin fibers are g...

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“…By analogy with the related ras proteins [5], it is assumed that rho proteins are inactive in the GDP-bound state and active in the GTP-bound form. Recently, several proteins have been described, apparently specifically regulating rho protein functions, such as a GTPase-activating protein (GAP) [6], a GDP dissociation inhibitor (GDI) [7] and a GDP dissociation stimulator (GDS) [8]. In addition, all three rho proteins can be ADP-ribosylated by the botulinum exoenzyme C3 [4,[9][10][11][12][13].…”

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confidence: 99%

Interaction of recombinant rho A GTP‐binding proteins with photoexcited rhodopsin

et al. 1990

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The small molecular mass GTP-binding proteins rho A, B and C are targets for ADP-ribosyltransferase activity of the botulinum exoenzyme C3. The possible interaction of recombinant rho A proteins expressed in E. coli with photoexcited rhodopsin was studied by reconstitution with bovine rod outer segment (ROS) membranes depleted of endogenous GTP-binding proteins by treatment with urea. As reported for C3 substrates present in untreated ROS membranes, ADP-ribosylation of recombinant rho A proteins, both normal and Val-14 mutant, by C3 was inhibited when reconstituted with illuminated compared to dark-adapted ROS membranes pretreated with urea. GDP reduced the light-induced inhibition, while GTP [S] and light inhibited ADP-ribosylation of rho A proteins in a synergistic manner.Rho protein; GTP-binding protein; Rhodopsin; Botulinum C3 ADP-ribosyltransferase; Bovine rod outer segment

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Partial purification and characterization of GDP dissociation stimulator (GDS) for the rho proteins from bovine brain cytosol

Cited by 43 publications

References 32 publications

SmgGDS Is a Guanine Nucleotide Exchange Factor That Specifically Activates RhoA and RhoC

SmgGDS Is a Guanine Nucleotide Exchange Factor That Specifically Activates RhoA and RhoC

Growth site localization of Rho1 small GTP-binding protein and its involvement in bud formation in Saccharomyces cerevisiae.

Interaction of recombinant rho A GTP‐binding proteins with photoexcited rhodopsin

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