The ubiquitin (Ub) pathway involves three sequential enzymatic steps that facilitate the conjugation of Ub and Ub-like molecules to specific protein substrates. The first step requires the ATP-dependent activation of the Ub C-terminus and the assembly of multi-Ub chains by the Ub-activating enzyme known as the E1 component. The Ub chain is then conjugated to the Ub-conjugating enzyme (E2) to generate an intermediate Ub-E2 complex. The Ub-ligase (E3) then catalyzes the transfer of Ub from E2 to the appropriate protein substrate. A wide range of enzymes facilitate in the proteolytic Ub pathway, including monoclonal nonspecific suppressor factor-beta (MNSF-beta), a subunit of MNSF, which is a lymphokine product of a murine T cell hybrid-oma that restricts the production of LPS-induced immunoglobulin secreting cells in an antigen-nonspecific manner. MNSF-beta is a ubiquitin-like fusion protein consisting of the ribosomal protein S30 and a protein that shares 36 % sequence identity with ubiquitin. This ubiquitin-like segment (Ubi-L) can be cleaved from MNSF-beta in the cytosol.
Synonyms: 40S ribosomal protein S30, asr1, FAU, FAU encoded ubiquitin like protein, FAU1, FBR MuSV associated ubiquitously expressed, Finkel Biskis Reilly murine sarcoma virus FBR MuSV ubiquitously expressed fox derived, Finkel Biskis Reilly murine sarcoma virus FBR MuSV ubiquitously expressed, Finkel Biskis Reilly murine sarcoma virus ubiquitously expressed, FLJ22986, Fub1, Fubi, MNSFbeta, Monoclonal nonspecic suppressor factor beta, Ribosomal protein S30, RPS30, S30, UBIM_HUMAN, Ubiquitin like protein fubi and ribosomal protein S30, Ubiquitin like protein fubi, Ubiquitin like S30 fusion protein, Ubiquitin-like protein FUBI.