Anti-STUB1 Antibody Picoband®

STUB1 (STIP1 homology and U-Box containing protein 1), also known as CHIP (C terminus of HSC70-Interacting Protein), is a human gene. This gene encodes a protein containing tetratricopeptide repeat and a U-box that functions as a ubiquitin ligase/cochaperone. The encoded protein binds to and ubiquitinates shock cognate 71 kDa protein (Hspa8) and DNA polymerase beta (Polb), among other targets. Mutations in this gene cause spinocerebellar ataxia, autosomal recessive 16. Alternative splicing results in multiple transcript variants. There is a pseudogene for this gene on chromosome 2.

Cell Cycle, Chaperones, Epigenetics and Nuclear Signaling, Heat Shock Proteins, Nuclear Signaling Pathways, Protein Trafficking, Signal Transduction, Ubiquitin & Ubiquitin Like Modifiers, Ubiquitin Ligases

E3 ubiquitin-protein ligase which targets misfolded chaperone substrates towards proteasomal degradation. Collaborates with ATXN3 in the degradation of misfolded chaperone substrates: ATXN3 restricting the length of ubiquitin chain attached to STUB1/CHIP substrates and preventing further chain extension. Ubiquitinates NOS1 in concert with Hsp70 and Hsp40. Modulates the activity of several chaperone complexes, including Hsp70, Hsc70 and Hsp90. Mediates transfer of non-canonical short ubiquitin chains to HSPA8 that have no effect on HSPA8 degradation. Mediates polyubiquitination of DNA polymerase beta (POLB) at 'Lys-41', 'Lys-61' and 'Lys-81', thereby playing a role in base-excision repair: catalyzes polyubiquitination by amplifying the HUWE1/ARF- BP1-dependent monoubiquitination and leading to POLB-degradation by the proteasome. Mediates polyubiquitination of CYP3A4. Ubiquitinates EPHA2 and may regulate the receptor stability and activity through proteasomal degradation. Acts as a co-chaperone for HSPA1A and HSPA1B chaperone proteins and promotes ubiquitin- mediated protein degradation (PubMed:27708256) . Negatively regulates the suppressive function of regulatory T-cells (Treg) during inflammation by mediating the ubiquitination and degradation of FOXP3 in a HSPA1A/B-dependent manner (PubMed:23973223) . Negatively regulates TGF-beta signaling by modulating the basal level of SMAD3 via ubiquitin-mediated degradation (PubMed:24613385) .

1. Entrez Gene: STUB1 STIP1 homology and U-box containing protein 1. 2. Heimdal, K., Sanchez-Guixe, M., Aukrust, I., Bollerslev, J., Bruland, O., Jablonski, G. E., Erichsen, A. K., Gude, E., Koht, J. A., Erdal, S., Fiskerstrand, T., Haukanes, B. I., Boman, H., Bjorkhaug, L., Tallaksen, C. M. E., Knappskog, P. M., Johansson, S. STUB1 mutations in autosomal recessive ataxias--evidence for mutation-specific clinical heterogeneity. Orphanet J. Rare Dis. 9: 146, 2014.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.