Calpain-induced proteolysis of beta-spectrins.
The calcium-activated neutral protease calpain is activated in several pathological conditions. Calpain usually hydrolyses one or only a few peptide bonds in its substrate. One prominent substrate for calpain is spectrin and it has been shown that alpha-spectrin is the preferred substrate. We now show that the beta-chain of spectrin is also a substrate for calpain proteolysis, and that the cleavage site in each beta-subunit is located at the very C-terminal part of the molecule. Surprisingly, beta1sigma-spectrin is cleaved at a different site than betaIsigma2- and betaIIsigma1-spectrins despite their high degree of sequence identity.
Löfvenberg
L
L
Department of Biochemistry, Umeå University, Sweden.
Backman
L
L
D000595:Amino Acid Sequence; D001483:Base Sequence; D002154:Calpain / Q000378:metabolism*; D017931:DNA Primers; D006868:Hydrolysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013049:Spectrin / Q000737:chemistry / Q000378:metabolism*