A gastrolith protein serving a dual role in the formation of an amorphous mineral containing extracellular matrix Academic Article uri icon


  • Despite the proclamation of Lowenstam and Weiner that crustaceans are the “champions of mineral mobilization and deposition of the animal kingdom,” relatively few proteins from the two main calcification sites in these animals, ie, the exoskeleton and the transient calcium storage organs, have been identified, sequenced, and their roles elucidated. Here, a 65-kDa protein (GAP 65) from the gastrolith of the crayfish, Cherax quadricarinatus, is fully characterized and its function in the mineralization of amorphous calcium carbonate (ACC) of the extracellular matrix is demonstrated. GAP 65 is a negatively charged glycoprotein that possesses three predicted domains: a chitin-binding domain 2, a low-density lipoprotein receptor class A domain, and a polysaccharide deacetylase domain. Expression of GAP 65 was localized to columnar epithelial cells of the gastrolith disk during premolt. In vivo …

publication date

  • January 1, 2008