Xwig1, a novel putative endoplasmic reticulum protein expressed during epithelial morphogenesis and in response to embryonic wounding

In a subtractive differential screening, we identified a novel gene with in teresting characteristics, termed Xenopus wounding induced g ene 1 (Xwig 1) . Xwig I encodes a novel protein of 912 amino acids containing 13 putative transmembrane segments and an evolutionarily conserved carboxy-terminal dom ain. Protein localization studies revealed that Xwig1 is anchored in cytopl asm ic structures, presumably the endoplasmic reticulum. Expression is larg ely confined to epithelial cells in regions that undergo morphogenetic proc esses, such as blastopore closure, hindgut closure, dorsal closure and opti c vesicle invagination. Interestingly, Xwig I transcription is activated in response to embryonic epidermal wounding. The wounding-induced transcripti on occurs downstream of the transient phosphorylation of extracellular sign al-regulated protein kinases and is in part mediated by Elk-l, but independ ent of dissection-induced FGF signalling. Thus, Xwig1 provides a molecular link between epithelial morphogenesis and wound healing.