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 interesting characteristics, termed Xenopus wounding induced gene 1 (Xwig1). Xwig1 encodes a novel protein of 912 amino acids containing 13 putative transmembrane segments and an evolutionarily conserved carboxy-terminal domain. Protein localization studies revealed that Xwig1 is anchored in cytoplasmic structures, presumably the endoplasmic reticulum. Expression is largely confined to epithelial cells in regions that undergo morphogenetic processes, such as blastopore closure, hindgut closure, dorsal closure and optic vesicle invagination. Interestingly, Xwig1 transcription is activated in response to embryonic epidermal wounding. The wounding-induced transcription occurs downstream of the transient phosphorylation of extracellular signal-regulated protein kinases and is in part mediated by Elk-1, but independent of dissection-induced FGF signalling. Thus, Xwig1 provides a molecular link between epithelial morphogenesis and wound healing.