Testican-3: a brain-specific proteoglycan member of the BM-40/SPARC/osteonectin family.

The testicans are a three-member family of secreted proteoglycans structurally related to the BM-40/secreted protein acidic and rich in cystein (SPARC) osteonectin family of extracellular calcium-binding proteins. In vitro studies have indicated that testicans are involved in the regulation of extracellular protease cascades and in neuronal function. Here, we describe the biochemical characterization and tissue distribution of mouse testican-3 as well as the inactivation of the corresponding gene.

Testican-1 is dispensable for mouse development.

Testicans are proteoglycans belonging to the BM-40/SPARC/osteonectin family of extracellular calcium-binding proteins. Testican-1 is strongly expressed in the brain and has been reported to modulate neuronal attachment and matrix metalloproteinase activation. Characterization of the mouse testican-1 gene (Ticn1), consisting of 12 exons out of which exon 3 is alternatively spliced, allowed the construction of a gene targeting construct.