Perlecan domain V of Drosophila melanogaster - Sequence, recombinant analysis and tissue expression

The C-terminal domain V of the basement membrane proteoglycan perlecan was previously shown to play a major role in extracellular matrix and cell inte ractions. A homologous sequence of 708 amino-acid residues from Drosophila has now been shown to be 33% identical to mouse perlecan domain V. It consi sts of three laminin G-type (LG) and epidermal growth factor-like (EG) modu les but lacks the EG3 module and a link region found in mammalian perlecans . Recombinant production of Drosophila perlecan domain V in mammalian cells yielded a 100-kDa protein which was folded into a linear array of three gl obular LG domains. Unlike the mouse counterpart, domain V from Drosophila w as not modified by glycosaminoglycans and endogenous proteolysis, due to th e absence of the link region. It showed moderate affinities for heparin and sulfatides but did not bind to chick alpha-dystroglycan or to various mamm alian basement membrane proteins. A single RGD sequence in LG3 of Drosophil a domain V was also incapable of mediating cell adhesion. Production of a p roteoglycan form of perlecan (approximate to 450 kDa) in one Drosophila cel l line could be demonstrated by immunoblotting with antibodies against Dros ophila domain V. A strong expression was also found by in situ hybridizatio n and immunohistology at various stages of embryonic development and expres sion was localized to several basement membrane zones. This indicates, as f or mammalian species, a distinct role of perlecan during Drosophila develop ment.