Disease relevance of RGS5

• Expression of regulator of G protein signalling protein 5 (RGS5) in the tumour vasculature of human renal cell carcinoma [1].
• A culture device demonstrates that hydrostatic pressure increases mRNA of RGS5 in neuroblastoma and CHC1-L in lymphocytic cells [2].
• Similarly, RGS-5 is overexpressed in highly angiogenic astrocytomas but not in hypoxia-inducible factor-1alpha (HIF-1alpha)-deficient tumors, which grow along preexisting brain capillaries without inducing neovessels [3].
• We identified regulator of G-protein signaling-5 (RGS-5) as an angiogenic pericyte marker at sites of physiologic and pathologic angiogenesis [3].

High impact information on RGS5

• A cDNA product identified from the inhibitor screen encodes a previously identified regulator of G-protein signaling, human RGS5 [4].
• Our genomewide linkage and candidate-gene-based association studies demonstrate that a replicated linkage peak for BP regulation on human chromosome 1q, homologous to mouse and rat quantitative trait loci for BP, contains at least three genes associated with BP levels in multiple samples: ATP1B1, RGS5, and SELE [5].
• Moreover, antitumor therapy, which reverses tumor vasculature to an almost normal morphology, results in down-regulation of RGS-5 transcription [3].
• In a mouse model of pancreatic islet cell carcinogenesis, RGS-5 is specifically induced in the vasculature of premalignant lesions during the "angiogenic switch" and further elevated in tumor vessels [3].
• Elevated levels of RGS-5 in pericytes are also observed during wound healing and ovulation indicating a strong correlation between RGS-5 expression and active vessel remodeling beyond tumor angiogenesis [3].

Biological context of RGS5

• Isolation, tissue expression, and chromosomal assignment of human RGS5, a novel G-protein signaling regulator gene [6].
• RGS5 bound to G alpha(i1), G alpha(i2), G alpha(i3), G alpha(o) and G alpha(q) but not to G alpha(s) and G alpha13 in the presence of GDP/AIF4-, and accelerated the catalytic rate of GTP hydrolysis of G alpha(i3) subunit [7].
• The amino acid sequence deduced from the cDNA possessed all consensus motifs of the RGS domain and showed closest homology to mouse RGS5 (90% identical), indicating that it was human RGS5 (hRGS5) [6].
• This study is the first to document alternative splicing of an RGS5 gene [8].
• The data suggest that the N-terminal of RGS5 may be important for protein translocation to the cell membrane [8].

Anatomical context of RGS5

• Gs signaling was unaffected, and, contrary to reports in other cell lines, RGS2-RGS5 did not appear to regulate adenylate cyclase directly in AVM [9].
• A human tissue RNA dot blot showed that RGS5 message is highest in aorta, followed by small intestine, stomach, and then heart [10].
• Expression profiling identifies smooth muscle cell diversity within human intima and plaque fibrous cap: loss of RGS5 distinguishes the cap [11].
• CONCLUSION: These data identify RGS5 as a new member of a short list of genes uniquely expressed in peripheral arteries but not coronary arteries [12].
• RESULTS: In situ hybridization localized RGS5 message to medial SMCs of peripheral arteries, including carotid, iliac, mammary, and renal arteries, but not accompanying veins [12].

Associations of RGS5 with chemical compounds

• N-Terminal Residues Control Proteasomal Degradation of RGS2, RGS4, and RGS5 in Human Embryonic Kidney 293 Cells [13].
• When expressed in 293T cells stably expressing angiotensin (Ang) AT1a receptors (AT1a-293T cells), RGS5 suppressed Ang II- and endothelin (ET)-1-induced intracellular Ca2+ transients [7].
• As observed for RGS5 mRNA levels in TG4 mice, RGS5 protein levels were increased in the atria of rats that were administered the beta adrenergic agonist isoproterenol during a 14 day period [14].

Other interactions of RGS5

• At low levels of stimulation RGS5 and RGS16 retained their differential Galpha activity, further highlighting that RGS proteins can discriminate between two very closely related Galpha subunits [15].
• The inhibition was not observed with RGS2, RGS5, and a functionally defective form of RGS16, RGS16(R169S/F170C) [16].
• Moreover in a competitive pull-down experiment, 14-3-3epsilon competes with Galphao for RGS4, but not for RGS5 [17].
• Characterization of RGS5 in regulation of G protein-coupled receptor signaling [7].
• Differential expression persisted in culture, inasmuch as RGS5 message was significantly higher in SMCs derived from arteries than from veins at real-time polymerase chain reaction [12].

Analytical, diagnostic and therapeutic context of RGS5

• By real-time RT-PCR, the ratio of RGS5 mRNA in RCC to that in normal kidney was 6.6 : 1 (p = 0.0012) [1].
• In situ hybridization showed strong expression of RGS5 in vessels within tumour cell nests [1].
• Northern blot analysis demonstrated that RGS5 levels were 3 fold higher in the atria of TG4 mice [14].
• Western blot analysis of a panel of rat tissues demonstrated that basal expression of RGS5 protein was confined to the heart and skeletal muscle [14].

References