Ca(2+)-regulated serine protease associated with the nuclear scaffold. Journal   Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research. Citation   Cell Growth Differ. 3(11):827-38 Publication date   1992 Nov Authors   Clawson GA Norbeck LL Hatem CL Rhodes C Amiri P McKerrow JH Patierno SR Fiskum G Investigators   Gary A. Clawson Grant agencies   National Cancer Institute Grants   NCI CA21141 NCI CA32946 NCI CA40145 MeSH headings   Calcium Nuclear Matrix Serine Endopeptidases MeSH qualifiers   physiology enzymology isolation & purification Abstract   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. Medline ID   93104208