Cloning and characterisation of the immunophilin X-CypA in Xenopus laevis.

This paper reports the cloning of Xenopus laevis, cyclophilin A gene, X-CypA. This study is the first developmental and functional characterisation in vivo of cyclophilin A in a vertebrate. X-CypA belongs to the superfamily of the immunophilin/PPIase proteins that can bind the immunosuppressant drug Cyclosporin A. Sequence analysis showed that X-CypA is highly conserved during evolution. RT-PCR and in situ hybridisation analysis showed that X-CypA expression is regulated during development and its transcripts are found in three major expression domains: nervous system, sensory organs and pronephros. Over-expression of X-CypA in embryos, analysed by in situ hybridisation and RT-PCR, leads to an expansion and disorganisation of the neural crest domain.