Affinage mechanistic annotation for ASB10 (human) Affinage Affinage (Claude Sonnet reading pass + Opus synthesis pass) 4 citations

Affinage mechanistic annotation for ASB10 (human)

Current model (mechanistic narrative)

ASB10 is a substrate-recognition E3 ubiquitin ligase that controls the abundance of specific client proteins and thereby regulates tissue homeostasis in the eye, vasculature, and heart [PMID:34285210, PMID:40399264]. As an E3 ligase it ubiquitylates the tumor endothelial marker TEM8, targeting it for proteasomal degradation so that loss of ASB10 elevates homeostatic TEM8 levels PMID:34285210. In the heart, ASB10 acts in the opposite direction on a different client: it binds HSP70 and competitively blocks STUB1-mediated ubiquitination of HSP70, stabilizing HSP70 and driving inflammation and accumulation of Ser394-phosphorylated HDAC2, which together exacerbate pressure-overload cardiac hypertrophy and fibrosis PMID:40399264. In trabecular meshwork cells ASB10 localizes to intracellular vesicles where it physically associates with HSP70 and with proteasomal (20S α4 subunit) and autophagic-lysosomal machinery, and its vesicle dynamics track autophagic flux, while ASB10 itself is not ubiquitinated PMID:23901248; silencing ASB10 reduces aqueous humor outflow facility, and a splice-altering coding variant links ASB10 to primary open-angle glaucoma PMID:22156576. A unified enzymatic mechanism connecting substrate selection across these tissues to a single biochemical activity has not been fully resolved in the available corpus.

Affinage mechanism profile (Affinage's own GO/Reactome grounding)

Dated findings (citation-anchored)

Year Confidence Finding PMIDs Journal
2011 Medium ASB10 silencing in perfused anterior segment organ culture reduced aqueous humor outflow facility by ~50% compared with control-infected anterior segments, demonstrating a functional role for ASB10 in trabecular meshwork outflow regulation. PMID:22156576 Human molecular genetics
2011 Medium ASB10 mRNA and protein are strongly expressed in trabecular meshwork, retinal ganglion cells, and ciliary body, as established by expression analysis in human ocular tissues. PMID:22156576 Human molecular genetics
2011 Medium A synonymous variant c.765C>T (Thr255Thr) in ASB10 affects an exon splice enhancer site and alters mRNA splicing in lymphoblasts of affected family members with POAG. PMID:22156576 Human molecular genetics
2013 Medium ASB10 localizes to intracellular vesicular structures in human trabecular meshwork (HTM) cells and co-localizes with markers of the ubiquitin-proteasomal pathway (ubiquitin, α4 subunit of 20S proteasome) and autophagic structures (LC3, p62, HDAC6, HSP70, Rab7, LAMP1), as shown by confocal and super-resolution structured illumination microscopy. PMID:23901248 Molecular vision
2013 Medium ASB10 physically interacts with HSP70 and with the α4 subunit of the 20S proteasome in HTM cells, as demonstrated by co-immunoprecipitation. PMID:23901248 Molecular vision
2013 Medium ASB10 itself is not ubiquitinated, despite its association with ubiquitin-mediated degradation pathway components in HTM cells. PMID:23901248 Molecular vision
2013 Medium Treatment of HTM cells with the autophagy/proteasome inhibitor MG132 significantly increased the number of small ASB10-stained vesicles, while autophagy inhibitors (wortmannin, bafilomycin A1) decreased them, indicating ASB10 vesicle dynamics are coupled to autophagic flux. PMID:23901248 Molecular vision
2021 Medium ASB10 functions as an E3 ubiquitin ligase that ubiquitylates TEM8 (tumor endothelial marker 8) for proteasomal degradation; ASB10 deficiency in triple-negative breast cancer results in elevated homeostatic TEM8 levels. PMID:34285210 Nature communications
2025 High Asb10 binds HSP70 and competitively blocks STUB1-mediated ubiquitination and proteasomal degradation of HSP70, thereby stabilizing HSP70 protein levels and exacerbating cardiac hypertrophic growth. PMID:40399264 Cell death & disease
2025 High Asb10 overexpression in vivo (AAV9-Asb10) worsens cardiac function and increases interstitial fibrosis after transverse aortic constriction (TAC), while Asb10 knockdown (AAV9-shAsb10) improves outcomes, establishing Asb10 as a pro-hypertrophic factor in pressure-overload heart failure. PMID:40399264 Cell death & disease
2025 Medium The pro-hypertrophic effects of Asb10 are mediated through HSP70 stabilization leading to cardiac inflammation and activation of phospho-HDAC2 at Ser394 (pHDAC2S394). PMID:40399264 Cell death & disease

Citations