STUB1 Protein, Human

STUB1 protein is an E3 ubiquitin protein ligase that cooperates with ATXN3 to regulate ubiquitin chain length on substrates and prevent chain extension. It ubiquitinates NOS1 through Hsp70/Hsp40 and regulates chaperone complexes (Hsp70, Hsc70, Hsp90). STUB1 Protein, Human is the recombinant human-derived STUB1 protein, expressed by E. coli , with tag free.

STUB1 Protein, an E3 ubiquitin-protein ligase, plays a pivotal role in targeting misfolded chaperone substrates for proteasomal degradation, collaborating with ATXN3 to regulate the ubiquitin chain length attached to STUB1 substrates and prevent further chain extension. It ubiquitinates NOS1 in conjunction with Hsp70 and Hsp40, modulating the activity of key chaperone complexes such as Hsp70, Hsc70, and Hsp90. Additionally, STUB1 mediates the transfer of non-canonical short ubiquitin chains to HSPA8 without affecting its degradation. The protein is involved in base-excision repair by catalyzing polyubiquitination of DNA polymerase beta (POLB), amplifying the HUWE1/ARF-BP1-dependent monoubiquitination and leading to POLB degradation. STUB1 also participates in the polyubiquitination of CYP3A4, ubiquitinates EPHA2 to potentially regulate receptor stability, acts as a co-chaperone for HSPA1A and HSPA1B, and negatively regulates TGF-beta signaling by modulating SMAD3 levels via ubiquitin-mediated degradation. Furthermore, STUB1 contributes to the degradation of FOXP3, SIRT6, and RIPK3, and likely downregulates PD-L1/CD274 plasma membrane expression. Its diverse functions underscore its significance in cellular homeostasis and immune regulation.

Human

E. coli

Tag Free

Q9UNE7 (M1-Y303)

10273  [NCBI]

Full Length

MKGKEEKEGGARLGAGGGSPEKSPSAQELKEQGNRLFVGRKYPEAAACYGRAITRNPLVAVYYTNRALCYLKMQQHEQALADCRRALELDGQSVKAHFFLGQCQLEMESYDEAIANLQRAYSLAKEQRLNFGDDIPSALRIAKKKRWNSIEERRIHQESELHSYLSRLIAAERERELEECQRNHEGDEDDSHVRAQQACIEAKHDKYMADMDELFSQVDEKRKKRDIPDYLCGKISFELMREPCITPSGITYDRKDIEEHLQRVGHFDPVTRSPLTQEQLIPNLAMKEVIDAFISENGWVEDY

Approximately 33 kDa, based on SDS-PAGE under reducing conditions.

• 
  ≥ 95%, as determined by reducing SDS-PAGE.

Solution

1.Supplied as a 0.22 μm filtered solution of PBS, pH 7.4.
2.Supplied as a 0.22 μm filtered solution of 20 mM Hepes, 6% trehalose, 0.02% Tween 20, 5 mM DTT, pH 8.2.
Please refer to the lot-specific COA for specific buffer information.

<1 EU/μg, determined by LAL method.

N/A.

Stored at -80°C for 1 year from date of receipt. It is stable at -20°C for 3 months after opening. It is recommended to freeze aliquots at -80°C for extended storage. Avoid repeated freeze-thaw cycles.

Shipping with dry ice.