Worm Breeder's Gazette 14(2): 46 (February 1, 1996)
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
Waksman Institute, Rutgers University, Piscataway, NJ 08855
Members of the tolloid/BMP-1 family of astacin zinc binding metalloproteases have been shown to be involved in the activation of extracellular growth factors, thus regulating various developmental events. The Drosophila tolloid gene genetically interacts with decapentaplegic (dpp), a member of the TGF-b-like family of growth factors, and is strongly implicated in enhancing its activity. The sea urchin tolloid/BMP-1 member, SpAN, is expressed temporally and spatially with univin, a TGF-b-like member, suggesting these two proteins may interact. Human BMP-1 has been copurified with other TGF-b-like BMPs, suggesting that these metalloproteases form complexes with the growth factors. tolloid/BMP-1 subfamily members contain one or more EGF and CUB (found in the complement proteins C1r and C1s) repeats C-terminal to the protease domain. These motifs, which vary in order and number between members, are strongly implicated in protein-protein interactions, allowing the specific recognition of different growth factors. We have previously characterized the two known members in C. elegans, tollish-1 (T24A11) and tollish-2 (R151). Both genes have an EGF and a CUB repeat following the metalloprotease domain. tollish-2 is unique among members in that it contains a thrombospondin (TSP) repeat, found in the extracellular matrix protein thrombospondin. We would like to determine the function of the tollish-1 and 2 genes, particularly their involvement with the processing and/ or activation of C. elegans growth factors. While we are searching for mutations, antisense RNA injections will be done in an attempt to obtain a phenotype. LacZ constructs to study the expression patterns of toh-1 and toh-2 are also being made. In addition to the tollish genes, there exists a handful of zinc metalloproteases recently identified by the genome sequencing consortium. We are currently analyzing the relationships of these metalloproteases via sequence comparison with other members. Two of the sequences analyzed from cosmids C05D11 and C07D10 are most closely related to HCE and LCE, hatching enzymes from the teleost Oryzias latipes. toh-2 and sequences from cosmid K04E7 are most closely related to SpAN and BP10, which are expressed in very early blastula stages of the sea urchin and have been suggested to play a role in differentiation and patterning of the embryo. We plan to characterize the gene encoded by K04E7, as well as other genes on cosmids which show a close relationship to tolloid/BMP-1 members, to determine their developmental roles in C. elegans.