NCBI Summary:
This gene encodes a member of the ankyrin repeat and suppressor of cytokine signaling (SOCS) box protein family. Members of this family can interact with the elongin B-C adapter complex via their SOCS box domain and further complex with the cullin and ring box proteins to form E3 ubiquitin ligase complexes. They may function to mediate the substrate-recognition of the E3 ubiquitin ligases. A transcribed pseudogene of this gene has been identified on chromosome 15. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2009]
General function
Protein metabolism and modification
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Comment
Ankyrin-repeat and SOCS box-containing protein 9 (ASB9) regulates ovarian granulosa cells function and MAPK signaling. Nosratpour S et al. (2021) Ankyrin-repeat and SOCS box-containing proteins (ASB) interact with the elongin B-C adapter via their SOCS box domain and with the cullin and ring box proteins to form E3 ubiquitin ligase complexes within the protein ubiquitination pathway. ASB9 in particular is a differentially expressed gene in ovulatory follicles (OFs) induced by the luteinizing hormone (LH) surge or hCG injection in ovarian granulosa cells (GC) while downregulated in growing dominant follicles. Although ASB9 has been involved in biological processes such as protein modification, the signaling network associated with ASB9 in GC is yet to be fully defined. We previously identified and reported ASB9 interactions and binding partners in GC including PAR1, TAOK1, and TNFAIP6/TSG6. Here, we further investigate ASB9 effects on target binding partners regulation and signaling in GC. CRISPR/Cas9-induced inhibition of ASB9 revealed that ASB9 regulates PAR1, TAOK1, TNFAIP6 as well as genes associated with proliferation and cell cycle progression such as PCNA, CCND2, and CCNE2 while CCNA2 was not affected. Inhibition of ASB9 was also associated with increased GC number and decreased caspase3/7 activity, CASP3 expression, and BAX/BCL2 ratio. Furthermore, ASB9 induction in OF in vivo 24 h post-hCG is concomitant with a significant decrease in phosphorylation levels of MAPK3/1 while pMAPK3/1 levels increased following ASB9 inhibition in GC in vitro. Together, these results provide strong evidence for ASB9 as a regulator of GC activity and function by modulating MAPK signaling likely through specific binding partners such as PAR1, therefore controlling GC proliferation and contributing to GC differentiation into luteal cells.//////////////////
Expression regulated by
LH
Comment
Gonadotropin regulation of ankyrin-repeat and SOCS-box protein 9 (ASB9) in ovarian follicles and identification of binding partners. Benoit G et al. (2019) Ankyrin-repeat and SOCS-box protein 9 (ASB9) is a member of the large SOCS-box containing proteins family and acts as the specific substrate recognition component of E3 ubiquitin ligases in the process of ubiquitination and proteasomal degradation. We previously identified ASB9 as a differentially expressed gene in granulosa cells (GC) of bovine ovulatory follicles. This study aimed to further investigate ASB9 mRNA and protein regulation, identify binding partners in GC of bovine ovulatory follicles, and study its function. GC were obtained from small follicles (SF: 2-4 mm), dominant follicles at day 5 of the estrous cycle (DF), and ovulatory follicles, 24 hours following hCG injection (OF). Analyses by RT-PCR showed a 104-fold greater expression of ASB9 in GC of OF than in DF. Steady-state levels of ASB9 in follicular walls (granulosa and theca cells) analyzed at 0, 6, 12, 18 and 24 hours after hCG injection showed a significant induction of ASB9 expression at 12 and 18 hours, reaching a maximum induction of 10.2-fold at 24 hours post-hCG as compared to 0 hour. These results were confirmed in western blot analysis showing strongest ASB9 protein amounts in OF. Yeast two-hybrid screening of OF-cDNAs library resulted in the identification of 10 potential ASB9 binding partners in GC but no interaction was found between ASB9 and creatine kinase B (CKB) in these GC. Functional studies using CRISPR-Cas9 approach revealed that ASB9 inhibition led to increased GC proliferation and modulation of target genes expression. Overall, these results support a physiologically relevant role of ASB9 in the ovulatory follicle by targeting specific proteins likely for degradation, contributing to reduced GC proliferation, and could be involved in the final GC differentiation into luteal cells.//////////////////