Disease relevance of RASA1

• The N-terminal domain (residues 3 to 307) of Sst2 (698 residues) has sequence similarity to the catalytic regions of bovine GTPase-activating protein and human neurofibromatosis tumor suppressor protein; segments in the C-terminal domain of Sst2 (between residues 417 and 685) are homologous to other RGS proteins [1].
• A GTPase-activating protein (GAP) specific for Galphaz was identified in brain, spleen, retina, platelet, C6 glioma cells, and several other tissues and cells [2].
• Changes in the expression of p21-Ras p120-GAP induced by growth factor treatment were examined in cultured Chinese hamster ovary (CHO) and human choriocarcinoma (BeWo) cells [3].

High impact information on RASA1

• A 360 residue region of the new peptide shows significant similarity to the known catalytic domains of both human and bovine GAP (GTPase activating protein) [4].
• Many of these signalling proteins, including phospholipase C gamma, GTPase-activating protein and phosphatidylinositol-3-OH kinase, contain src-homology 2 (SH2) domains, which bind with high affinity and specificity to tyrosine-phosphorylated sequences [5].
• Full-length neurofibromin is a GTPase activating protein (GAP) for the Ras proto-oncogene product [6].
• On GTP hydrolysis induced by the GTPase-activating protein ArfGAP1, the complexes were disassembled and AP-1 dissociated from the membrane [7].
• RGSZ1, a Gz-selective RGS protein in brain. Structure, membrane association, regulation by Galphaz phosphorylation, and relationship to a Gz gtpase-activating protein subfamily [8].

Biological context of RASA1

• By using antisera specific to other mediators of signal transduction that contain SH2 domains for immunoprecipitation, it was demonstrated that VEGF promotes phosphorylation of phosphatidylinositol 3-kinase, Ras GTPase activating protein (GAP), and the oncogenic adaptor protein NcK [9].
• A novel protein harboring a 280-amino acid region from an Alu-linked repetitive sequence (bovine Alu-like dimer-driven family) was isolated from a bovine brain S-100 fraction using monoclonal antibodies against a rat GTPase-activating protein that shares the same epitope [10].
• RGS9, a member of the family of regulators of G protein signaling (RGS), serves as a GTPase-activating protein (GAP) for the transducin alpha-subunit (Gtalpha) in the vertebrate visual transduction cascade [11].
• A cDNA probe was used to assign RASA to the region 2.4-qter of bovine Chromosome (Chr) 7 by in situ hybridization [12].
• RASA contains a polymorphic microsatellite and maps to bovine syntenic group U22 on chromosome 7q2.4-qter [12].

Anatomical context of RASA1

• The purification of a Rap1 GTPase-activating protein from bovine brain cytosol [13].
• Our evidence for destabilization of microtubules by formation of apotubulin and by nucleotide exchange to form terminal TuD subunits suggests that microtubule dynamics can be regulated in cells by an exchange factor that generates apotubulin subunits, or by a GTPase activating protein that forms TuD subunits at microtubule ends [14].
• An isoform of RGS9 was recently identified as the GTPase activating protein in bovine and mouse rod and cone photoreceptors [15].
• Partial purification of a GTPase-activating protein for rap2b from bovine brain membranes [16].

Associations of RASA1 with chemical compounds

• Heparin failed to alter 5-HT uptake by SMC, but inhibited the stimulation of tyrosine phosphorylation of GTPase-activating protein, a proposed intermediate in the 5-HT stimulatory process [17].
• These mutations did not affect the guanine nucleotide-binding activity or GTPase activity in the absence or presence of bovine GTPase-activating protein (GAP) [18].
• Ginkgo biloba extract 501 (EGb 501), which has been demonstrated to act as an antioxidant, was found to block both the elevated O2.- and the proliferative and hypertrophic influences of 5-HT on SMCs, but not to directly inhibit the associated activation of NAD(P)H oxidase or the stimulation of phosphorylation of GTPase-activating protein (GAP) [19].

Analytical, diagnostic and therapeutic context of RASA1

• PCR analysis of a panel of somatic hybrid lines allowed the assignment of RASA to the unassigned syntenic group 22 (U22) and thus localizes U22 on Chr 7 [12].

References