Worm Breeder's Gazette 13(3): 50 (June 1, 1994)
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.
The annexins are calcium-dependent, phospholipid-binding proteins that may function in exocytosis, membrane structure and permeation, and signal transduction. In order to establish a system for genetic analysis of their hypothetical functions, we have been characterizing the annexins of the nematode, C. elegans. Annexins were isolated from postmicrosomal supernatants by calcium-dependent binding to lipid vesicles. EGTA extracts of these vesicles appear to contain primarily a single protein of mass 32kDa when examined by SDS-PAGE. Peptides derived from this protein were sequenced and verified that the worm protein is an annexin. An antiserum was raised to the worm annexin and was found to react almost exclusively with a 32kDa band in Western blots of worm homogenates. The antiserum was used to isolate cDNAs for the protein from a lambda gt11 library (kindly provided by A. Fire). The sequence of the worm annexin is 42% identical to that of bovine annexin IV, the closest vertebrate homolog. The single annexin gene was physically mapped to the vicinity of dpy-17 in LGIII. One of three cDNA clones isolated contained a 15 base splice insertion encoding five amino acids near the N-terminus. This insertion contained THR and TYR residues that align exactly with phosphorylation sites in mammalian annexins for protein kinase C and the src kinase.