UBAP2 (F6E7I) Rabbit Monoclonal Antibody recognizes endogenous levels of total UBAP2 protein. Based on the sequence of the peptide antigen, this antibody is not expected to detect UBAP2L protein.

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Lys504 of human UBAP2 protein.

Ubiquitin-associated protein 2 (UBAP2) and its paralog, UBAP2-like (UBAP2L), function redundantly as the human orthologs of yeast Def1 in the last resort pathway, the cellular mechanism that ubiquitinates and degrades RNA polymerase II (RNAPII) in response to transcription stress (1,2). UBAP2 acts by recruiting Elongin-Cul5 ubiquitin ligase to degrade RNAPII at sites where transcription is stalled due to DNA damage (1,2). At DNA lesion sites, UBAP2-mediated removal of RNAPII allows repair proteins, including those involved in transcription-coupled nucleotide excision repair (TC-NER), to access the lesions (1,3). This process serves as a critical backup mechanism when TC-NER fails to resolve DNA damage on its own (1).

In hepatocellular carcinoma (HCC) tissues, UBAP2 is downregulated, and higher UBAP2 expression levels in these tissues are associated with a better prognosis, making UBAP2 a novel biomarker for prognostic prediction (4). When UBAP2 forms a complex with annexin A2, it promotes the degradation of annexin A2 protein through ubiquitination, thereby inhibiting HCC progression (4). Circular RNA UBAP2 (circUBAP2) has been shown to promote the progression of several cancers, including osteosarcoma, ovarian, prostate, and cervical cancer (5-8). UBAP2 is also associated with osteoporosis, acting as a potential biomarker and therapeutic target (9).