PSMD4 Antibody

In eukaryotic cells, selective breakdown of cellular proteins is ensured by two distinct pathways. First, appropriate proteins are tagged for degradation by ubiquitination. Second, these multiubiquitinated proteins are degraded by the highly selective 26S Proteasome protein-destroying machinery. At specific stages of development, embryo- and tissue-specific components of the 26S Proteasome are formed, which are termed Rpn10a through Rpn10e, or alternatively pUb-R2 through pUb-R5. All members of this family can be generated by a single Rpn10 gene by developmentally regulated alternative splicing. The pUb-R2 subunit, originally identified as S5a (also designated antisecretory factor and multiubiquitin chain binding protein) is ubiquitously expressed and may perform proteolysis constitutively in a wide variety of cells. pUb-R4 and pUb-R5 may have embryo- or tissue-specific expression and may play specialized roles in early embryonic development.