Disease relevance of UBE2B

• Whereas MCF10A cells engineered to overexpress ectopic RAD6B are significantly more resistant to ADR and cisplatin as compared to empty vector-transfected cells, MCF10A cells stably transfected with antisense RAD6B display hypersensitivity to these damage-inducing drugs [1].
• Since heterozygous male mice and even knockout female mice are completely normal and fertile and thus able to transmit the defect, similar hHR6B mutations may cause male infertility in man [2].

High impact information on UBE2B

• We have cloned the two human RAD6 homologs, designated HHR6A and HHR6B [3].
• Constitutive overexpression of exogenous human HR6B cDNA into normal-behaving MCF10A human breast epithelial cells induced cell-cell fusion that resulted in generation of multinucleated cells, centrosome amplification, multipolar mitotic spindles, aneuploidy, and ability for anchorage-independent growth [4].
• A survey of E1 and E2 isoform distribution in selected cell lines demonstrates that Ubc2 isoforms are the predominant intracellular ubiquitin carrier protein [5].
• Inclusion of actinomycin D abolishes both basal and ADR-induced RAD6B transcription indicating that ADR-induced effects on RAD6B transcription result from an increase in transcriptional activity rather than from regulation of RAD6B mRNA stability [1].
• This review attempts to integrate recent knowledge regarding flagellar components that could be related to proteasome components and, therefore, could be targets of UBE2B in the spermatid [6].

Biological context of UBE2B

• The HHR6B gene was assigned to human chromosome 5q23-q31, whereas the HHR6A gene was localized on the human X chromosome (Xq24-q25) [7].
• The deduced amino acid sequence is 77% identical to the human E2, HHR6A and HHR6B [8].
• In spermatogenesis, there appears to be a special requirement for certain components of the ubiquitin system, as exemplified in human and mouse by mutation of USP9Y and HR6B, respectively [9].
• (CGG) trinucleotide repeat polymorphism in the 5' region of the HHR6B gene: the human homolog of the yeast DNA repair gene RAD6 [10].

Associations of UBE2B with chemical compounds

• Exposure of MCF10A cells to adriamycin (ADR) causes enhancement in the levels of RAD6B mRNA and protein [1].

Other interactions of UBE2B

• The human RAD18 gene product interacts with HHR6A and HHR6B [11].

Analytical, diagnostic and therapeutic context of UBE2B

• Southern blot analysis points to an X and an autosomal localization of HHR6A and HHR6B, respectively, in the mouse [7].

References