Cleavage of the myristoylated alanine-rich C kinase substrate (MARCKS) by cysteine cathepsins in cells and tissues of stefin B-deficient mice.
The myristoylated alanine-rich C kinase substrate (MARCKS) is a substrate of protein kinase C (PKC). Besides regulation at the level of gene transcription, MARCKS concentrations within the cell are also regulated by proteolytic cleavage by cathepsins and calpains, which are cysteine proteinases. Stefin B (cystatin B) is an endogenous inhibitor of lysosomal cysteine cathepsins, but not calpains. We have observed increased cleavage of MARCKS in brain and macrophages, but not in liver and kidney extracts of stefin B-deficient mice compared to wild-type mice. Processing of cathepsin B was unaltered in the brain of stefin B-deficient mice and we conclude that increased cleavage of MARCKS could be attributed to the lack of inhibitor.
Kopitar-Jerala
Natasa
N
Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia. natasa.kopitar@ijs.si
Turk
Boris
B
D000818:Animals; D002403:Cathepsins / Q000378:metabolism*; D055313:Cystatin B; D015891:Cystatins / Q000172:deficiency*; D003545:Cysteine / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D009928:Organ Specificity; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D014020:Tissue Extracts / Q000378:metabolism
C524992:Cstb protein, mouse; D015891:Cystatins; D047908:Intracellular Signaling Peptides and Proteins; C000619711:Marcks protein, mouse; D008565:Membrane Proteins; D014020:Tissue Extracts; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D055313:Cystatin B; D002403:Cathepsins; D003545:Cysteine