The nuclear scaffold (NS) is a proteinaceous network of orthogonally arrayed intermediate filament proteins, termed lamins, which is responsible for nuclear structure. Recent work has demonstrated that a subset of lamins A/C is proteolytically cleaved to produce an ATP-binding protein. This proteolytic cleavage is accomplished by a NS protease activity, which shows a considerable selectivity for lamins A/C and is stringently regulated by Ca2+ in vitro, suggesting that it might also participate in control of NS breakdown in various scenarios. Here, we identify the major NS protease as a novel serine protease with a predominantly chymotryptic-like substrate preference, and we show that even transient perturbations in cytosolic Ca2+ have significant effects on the NS protease activity. This NS protease activity shows extensive similarities to the multicatalytic proteinase complex. In addition to a potential role in control of NS breakdown at mitosis and/or under pathological conditions, this NS protease is also strategically located for other functions, such as inactivation of various oncogenic proteins or maturation-promoting factor.
|Original language||English (US)|
|Number of pages||12|
|Journal||Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research|
|State||Published - Nov 1992|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology