IDENTIFICATION OF PLEXIN FAMILY MOLECULES IN MICE

By screening of E17.5 mouse brain cDNA libraries, we isolated two cDNA s encoding new plexin-like proteins. Sequencing revealed that these tw o proteins were type 1 membrane proteins which showed over 60% identit y at the amino acid level to mouse plexin 1. Moreover, putative extrac ellular segments of these two proteins had three repeats of a cysteine -rich domain which is a common motif for plexin proteins. Thus, we nam ed these two proteins mouse plexin 2 and mouse plexin 3. We obtained m ouse plexin 3 cDNA clones in which a part of protein-coding region was deleted. Also, Northern blot analysis showed molecular heterogeneity in mouse plexin 2 mRNAs. These findings indicate that, in the mouse, p lexins comprise a molecular family (the plexin family). (C) 1996 Acade mic Press, Inc.