The region of homology between the yeast SST2 gene product, which regulates G protein signaling, and the C. elegans
EGL-10 protein defines the 'regulator of G protein signaling' (RGS) domain . Proteins containing the RGS
domain constitute a family of molecules that appear to function as negative regulators of heterotrimeric G protein signaling.
Several mammalian RGS proteins function as GTPase-activating proteins for G protein alpha-subunits. Based on Southern blotting, Druey et al. (1996) estimated that there are at least 15 human RGS family
members.
NCBI Summary:
Regulator of G protein signaling (RGS) family members are regulatory molecules that act as GTPase activating proteins (GAPs) for G alpha subunits of heterotrimeric G proteins. RGS proteins are able to deactivate G protein subunits of the Gi alpha, Go alpha and Gq alpha subtypes. They drive G proteins into their inactive GDP-bound forms. Regulator of G protein signaling 2 belongs to this family. The protein acts as a mediator of myeloid differentiation and may play a role in leukemogenesis. [provided by RefSeq, Aug 2009]
General function
Intracellular signaling cascade
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Ovulation, Oocyte maturation, Early embryo development
Comment
Regulation of the regulator of G protein signaling 2 expression and cellular localization by PKA and PKC pathways in mouse granulosa cells. Yeh HY et al. (2018) G protein-coupled receptor (GPCR) activation-mediated PKA and PKC pathways have been recognized to be important in ovarian physiology. Expression of regulator of G-protein signaling 2 (RGS2) has been reported in ovarian granulosa cells. The detailed mechanisms in PKA- and PKC-regulated RGS2 expression and cellular translocation in granulosa cells remain mostly unclear. PKA activator 8-bromo-cAMP and PKC activator phorbol-12, 13-didecanoate appeared to rapidly elevate both protein and mRNA levels and promoter activation of RGS2 gene. Two consensus Sp1 elements within the shortest 78 bp fragment of RGS2 promoter sequence were essential for the full responsiveness to PKA and PKC. PKC activation appeared to increase the RGS2 translocation from nucleus to cytosol. PKA- and PKC-mediated RGS2 transcription in a Sp-1-dependent manner and a PKC-mediated RGS2 intracellular translocation were noted in granulosa cells.//////////////////
Inhibition of the Binding between RGS2 and β-Tubulin Interferes with Spindle Formation and Chromosome Segregation during Mouse Oocyte Maturation In Vitro. Jiang MX et al. (2016) RGS2 is a negative regulator of G protein signaling that contains a GTPase-activating domain and a β-tubulin binding region. This study aimed to determine the localization and function of RGS2 during mouse oocyte maturation in vitro. Immunofluorescent staining revealed that RGS2 was widely expressed in the cytoplasm with a greater abundance on both meiotic spindles and first/second polar bodies from the fully-grown germinal vesicle (GV) stage to the MII stages. Co-expression of RGS2 and β-tubulin could also be detected in the spindle and polar body of mouse oocytes at the MI, AI, and MII stages. Inhibition of the binding site between RGS2 and β-tubulin was accomplished by injecting anti-RGS2 antibody into GV-stage oocytes, which could result in oocytes arrest at the MI or AI stage during in vitro maturation, but it did not affect germinal vesicle breakdown. Moreover, injecting anti-RGS2 antibody into oocytes resulted in a significant reduction in the rate of first polar body extrusion and abnormal spindle formation. Additionally, levels of phosphorylated MEK1/2 were significantly reduced in anti-RGS2 antibody injected oocytes compared with control oocytes. These findings suggest that RGS2 might play a critical role in mouse oocyte meiotic maturation by affecting β-tubulin polymerization and chromosome segregation.//////////////////
Genomic assessment of follicular marker genes as pregnancy predictors for human IVF. Hamel M et al. Embryo selection efficiency in human IVF procedure is still suboptimal as shown by low pregnancy rates with single embryo transfer (SET). Bidirectional communication between the oocyte and follicular cells (FC) is essential to achieve developmental competence of the oocyte. Differences in the gene expression profile of FCs from follicles leading to pregnancy could provide useful markers of oocyte developmental competence. FCs were recovered by individual follicle puncture. FC expression levels of potential markers were assessed by Q-PCR with an intra-patient and an inter-patient analysis approach. Using gene expression, a predictive model of ongoing pregnancy was investigated. Using intra-patient analysis, 4 candidate genes, phosphoglycerate kinase 1 (PGK1), regulator of G-protein signalling 2 (RGS2), regulator of G-protein signalling 3 (RGS3) and cell division cycle 42 (CDC42) showed a difference between FCs from follicles leading to a pregnancy or developmental failure. The best predictors for ongoing pregnancy were PGK1 and RGS2. Additionally, inter-patient analysis revealed differences in FC expression for PGK1 and CDC42 between follicles leading to a transferred embryo with positive pregnancy results and those with negative results. Both inter-patient and intra-patient approaches must be taken into consideration to delineate gene expression variations in the context of follicular competence. A predictor model using biomarkers could improve the efficiency of predicting developmental competence of oocytes. These new approaches provide useful tools in the context of embryo selection and in the improvement of pregnancy rates with SET.
Ujioka T, et al 2000 reported the expression of regulator of G-protein signaling protein-2 gene
in the rat ovary at the time of ovulation.
Immature Wistar rats were primed with 10
IU eCG s.c., and 48 h later the 12-h ovulatory process was initiated by 10 IU
hCG (a homolog of LH) s.c. Ovarian RNA was extracted at 0, 2, 4, 8, 12, and 24
h after injecting the animals with hCG. The RNA extracts were used for reverse
transcription-polymerase chain reaction differential display to detect gene
expression in the stimulated ovarian tissue. Two of the amplified cDNAs that
were upregulated within 2 h after the ovaries had been stimulated by hCG were
homologous to segments of the mouse gene for RGS2. In situ hybridization
indicated that the RGS2 mRNA was expressed in the granulosa layer of mature
follicles. In conclusion, the gene for RGS2, which is known to regulate
membrane signaling pathways, is transcribed in ovarian follicles in response
to an ovulatory dose of gonadotropin.
Expression regulated by
LH
Comment
Luteinizing Hormone Receptor Gene and Regulator of G-protein Signaling 2 Gene Expression Level and Association with Oocyte Maturity in In vitro Fertilization/Intracytoplasmic Sperm Injection Cycle. Chokjirawat T et al. (2018) The aim is to study the relation and distribution in gene expression level of the luteinizing hormone receptor (LHR) gene and regulator of G-protein signaling 2 (RGS2) gene expression with oocyte maturation. This cross-sectional study was undertaken in an instruction-based tertiary care infertility unit, department of obstetrics and gynecology. After controlled ovarian hyperstimulation, cumulus granulosa cells (CCs) from 59 oocytes among 18 women being treated by in vitro fertilization/intracytoplasmic sperm injection cycle technique from November 2015 to January 2016 were collected on the day of oocyte retrieval. Total RNA was extracted and converted to cDNA in individual oocytes. LHR and RGS2 gene levels were measured and analyzed using digital droplet polymerase chain reaction. Gene expression level was analyzed using software STATA, version 14.0 (College Station, TX: StataCorp LP, USA). CCs were obtained from 59 cumulus-oocyte complexes (COC), 46 COC from metaphase II (CCMII), 13 COC from metaphase I, and GV oocyte (CCMI + GV). The RGS2 gene expression level, when compared with the housekeeping gene in CCMII and CCMI + GV, was 0.15 (0.05-0.52) and 0.08 (0.02-0.27), respectively. The LHR gene expression when compared with the housekeeping gene in CCMII and CCMI + GV did not differ and was quite in the same value that was 0.02 (0.00-0.11) and 0.02 (0.00-0.06), respectively. This study showed that LHR gene expression did not differ in between oocyte groups. Even though the median of RGS2 gene expression was more in the mature oocyte group, the result was inconclusive due to scattering and overlapping of gene expression data between oocyte groups.//////////////////
Expression and Regulation of Regulator of G-Protein Signaling Protein-2 (RGS2) in Equine and Bovine Follicles prior to Ovulation: Molecular Characterization of RGS2 Transactivation in Bovine Granulosa Cells. Sayasith K et al. (2014) The luteinizing hormone preovulatory surge stimulates several signal pathways essential for ovulation, and the regulator of G-protein signaling protein-2 (RGS2) is thought to be involved in this process. The objectives of this study were to characterize the regulation of RGS2 transcripts in equine and bovine follicles prior to ovulation and to determine its transcriptional control in bovine granulosa cells. To assess the regulation of equine RGS2 prior to ovulation, RT-PCR was performed using total RNA extracted from equine follicles collected at various times after human chorionic gonadotropin (hCG) injection. Results showed that RGS2 mRNA levels were very low at 0 h but markedly increased 12-39 h post-hCG (P < 0.05). In the bovine species, results revealed that RGS2 mRNA levels were low in small and dominant follicles and in ovulatory follicles obtained at 0 h, but markedly increased in ovulatory follicles 6-24 h post-hCG (P < 0.05). To study the molecular control of RGS2 expression, primary cultures of bovine granulosa cells were used. Stimulation with forskolin induced an up-regulation of RGS2 mRNA in vitro. Studies using 5'-deletion mutants identified a minimal region containing full-length basal and forskolin-inducible RGS2 promoter activities. Site-directed mutagenesis indicated that these activities were dependent on CRE and ETS1 cis-elements. Electrophoretic mobility shift assays confirmed the involvement of these elements and revealed their interactions with CREB1 and ETS1 proteins. Chromatin immunoprecipitation assays confirmed endogenous interactions of these proteins with the RGS2 promoter in granulosa cells. Forskolin-inducible RGS2 promoter activity and mRNA expression were markedly decreased by PKA and ERK1/2 inhibitors, and treatment with an antagonist of PGR (RU486) and inhibitors of PTGS2 (NS398) and EGFR (PD153035) blocked the forskolin-dependent RGS2 transcript expression, suggesting the importance of RGS2 in ovulation. Collectively, this study reports for the first time the gonadotropin-dependent up-regulation of RGS2 in equine and bovine preovulatory follicles and presents some of the regulatory controls involved in RGS2 gene expression in granulosa cells.//////////////////
Ovarian localization
Oocyte, Cumulus, Granulosa
Comment
Genomic assessment of human cumulus cell marker genes as predictors of oocyte developmental competence: impact of various experimental factors. Feuerstein P et al. Single embryo transfer (SET) is the most successful way to reduce the frequency of multiple pregnancies following in vitro fertilisation. However, selecting the embryo for SET with the highest chances of pregnancy remains a difficult challenge since morphological and kinetics criteria provide poor prediction of both developmental and implantation ability. Partly through the expression of specific genes, the oocyte-cumulus interaction helps the oocyte to acquire its developmental competence. Our aim was therefore to identify at the level of cumulus cells (CCs) genes related to oocyte developmental competence.
Follicle stages
Antral, Preovulatory
Comment
Semi-quantitative measurement of specific proteins in human cumulus cells using reverse phase protein array. Puard V 2013 et al.
BACKGROUND
The ability to predict the developmental and implantation ability of embryos remains a major goal in human assisted-reproductive technology (ART) and most ART laboratories use morphological criteria to evaluate the oocyte competence despite the poor predictive value of this analysis. Transcriptomic and proteomic approaches on somatic cells surrounding the oocyte (granulosa cells, cumulus cells [CCs]) have been proposed for the identification of biomarkers of oocyte competence. We propose to use a Reverse Phase Protein Array (RPPA) approach to investigate new potential biomarkers of oocyte competence in human CCs at the protein level, an approach that is already used in cancer research to identify biomarkers in clinical diagnostics.
METHODS
Antibodies targeting proteins of interest were validated for their utilisation in RPPA by measuring siRNA-mediated knockdown efficiency in HEK293 cells in parallel with Western blotting (WB) and RPPA from the same lysates. The proteins of interests were measured by RPPA across 13 individual human CCs from four patients undergoing intracytoplasmic sperm injection procedure.
RESULTS
The knockdown efficiency of VCL, RGS2 and SRC were measured in HEK293 cells by WB and by RPPA and were acceptable for VCL and SRC proteins. The antibodies targeting these proteins were used for their detection in human CCs by RPPA. The detection of protein VCL, SRC and ERK2 (by using an antibody already validated for RPPA) was then carried out on individual CCs and signals were detected for each individual sample. After normalisation by VCL, we showed that the level of expression of ERK2 was almost the same across the 13 individual CCs while the level of expression of SRC was different between the 13 individual CCs of the four patients and between the CCs from one individual patient.
CONCLUSIONS
The exquisite sensitivity of RPPA allowed detection of specific proteins in individual CCs. Although the validation of antibodies for RPPA is labour intensive, RRPA is a sensitive and quantitative technique allowing the detection of specific proteins from very small quantities of biological samples. RPPA may be of great interest in clinical diagnostics to predict the oocyte competence prior to transfer of the embryo using robust protein biomarkers expressed by CCs.
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Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: type: null mutation fertility: fertile Comment: Regulator of G-protein signaling-2 mediates vascular smooth muscle relaxation and blood pressure. Tang KM et al. (2003) Nitric oxide (NO) inhibits vascular contraction by activating cGMP-dependent protein kinase I-alpha (PKGI-alpha), which causes dephosphorylation of myosin light chain (MLC) and vascular smooth muscle relaxation. Here we show that PKGI-alpha attenuates signaling by the thrombin receptor protease-activated receptor-1 (PAR-1) through direct activation of regulator of G-protein signaling-2 (RGS-2). NO donors and cGMP cause cGMP-mediated inhibition of PAR-1 and membrane localization of RGS-2. PKGI-alpha binds directly to and phosphorylates RGS-2, which significantly increases GTPase activity of G(q), terminating PAR-1 signaling. Disruption of the RGS-2-PKGI-alpha interaction reverses inhibition of PAR-1 signaling by nitrovasodilators and cGMP. Rgs2-/- mice develop marked hypertension, and their blood vessels show enhanced contraction and decreased cGMP-mediated relaxation. Thus, PKGI-alpha binds to, phosphorylates and activates RGS-2, attenuating receptor-mediated vascular contraction. Our study shows that RGS-2 is required for normal vascular function and blood pressure and is a new drug development target for hypertension.//////////////////