| First Author | Finley D | Year | 1984 |
| Journal | Cell | Volume | 37 |
| Issue | 1 | Pages | 43-55 |
| PubMed ID | 6327059 | Mgi Jnum | J:87880 |
| Mgi Id | MGI:3028425 | Doi | 10.1016/0092-8674(84)90299-x |
| Citation | Finley D, et al. (1984) Thermolability of ubiquitin-activating enzyme from the mammalian cell cycle mutant ts85. Cell 37(1):43-55 |
| abstractText | Ubiquitin, a 76 residue protein, occurs in eucaryotic cells either free or covalently joined to a variety of protein species. Previous work suggested that ubiquitin may function as a signal for attack by proteinases specific for ubiquitin-protein conjugates. We show that the mouse cell line ts85 , a previously isolated cell cycle mutant, is temperature-sensitive in ubiquitin-protein conjugation, and that this effect is due to the specific thermolability of the ts85 ubiquitin-activating enzyme (E1). From E1 thermoinactivation kinetics in mixed (wild-type plus ts85 ) extracts, and from copurification of the determinant of E1 thermolability with E1 in ubiquitin-affinity chromatography, we conclude that the determinant of E1 thermolability is contained within the E1 polypeptide. ts85 cells fail to degrade otherwise short-lived intracellular proteins at the nonpermissive temperature (accompanying paper), demonstrating that degradation of the bulk of short-lived proteins in this higher eucaryotic cell proceeds through a ubiquitin-dependent pathway. We discuss possible roles of ubiquitin-dependent pathways in DNA transactions, the cell cycle, and the heat shock response. |
