anti-Ubiquitin+1, pAb

Ubiquitin+1 (Ub+1) is a novel mutant form of ubiquitin that can be produced through a process known as molecular frame shift. Ub+1 can be polyubiquitinated to produce aberrant polyubiquitin chains that inhibit the 26S proteasome. Especially ub+1 is accumulated in aggregates containing amyloid-β and phosphorylated-tau. Elevated expression of Ub+1 mRNA and protein has been observed in the brains of patients with Alzheimer's disease. Also Ub+1 acts as an aggravating factor in polyglutamine-induced neurodegeneration. Protein modifier which can be covalently attached to target lysines either as a monomer or as a lysine-linked polymer. Attachment to proteins as a Lys-48-linked polymer usually leads to their degradation by proteasome. Attachment to proteins as a monomer or as an alternatively linked polymer does not lead to proteasomal degradation and may be required for numerous functions, including maintenance of chromatin structure, regulation of gene expression, stress response, ribosome biogenesis and DNA repair.