ECB-ART-42603J Biochem 2013 Jan 01;1531:51-61. doi: 10.1093/jb/mvs118.
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Roles of CUB and LDL receptor class A domain repeats of a transmembrane serine protease matriptase in its zymogen activation.
Matriptase is a type II transmembrane serine protease containing two complement proteases C1r/C1s-urchin embryonic growth factor-bone morphogenetic protein domains (CUB repeat) and four low-density lipoprotein receptor class A domains (LDLRA repeat). The single-chain zymogen of matriptase has been found to exhibit substantial protease activity, possibly causing its own activation (i.e. conversion to a disulfide-linked two-chain fully active form), although the activation seems to be mediated predominantly by two-chain molecules. Our aim was to assess the roles of CUB and LDLRA repeats in zymogen activation. Transient expression studies of soluble truncated constructs of recombinant matriptase in COS-1 cells showed that the CUB repeat had an inhibitory effect on zymogen activation, possibly because it facilitated the interaction of two-chain molecules with a matriptase inhibitor, hepatocyte growth factor activator inhibitor type-1. By contrast, the LDLRA repeat had a promoting effect on zymogen activation. The effect of the LDLRA repeat seems to reflect its ability to increase zymogen activity. The proteolytic activities were higher in pseudozymogen forms of recombinant matriptase containing the LDLRA repeat than in a pseudozymogen without the repeat. Our findings provide new insights into the roles of these non-catalytic domains in the generation of active matriptase.
PubMed ID: 23038671
PMC ID: PMC3527997
Article link: J Biochem
Genes referenced: LOC582189 LOC752081 LOC756768
References [+] :
Bork, The CUB domain. A widespread module in developmentally regulated proteins. 1993, Pubmed