A new family of cyclophilins with an RNA recognition motif that interact with members of the trx/MLL protein family in Drosophila and human cells.

A new family of cyclophilins with an RNA recognition motif (RRM) has members in vertebrates, roundworms and flatworms. We have identified a Drosophilacyclophilin, Dcyp33, with a high degree of amino acid sequence identity and similarity with other members of the family. Dcyp33 interacts through its RRM domain with the third PHD finger of trithorax. This interaction is conserved in the human homologues of these proteins, Cyp33 and MLL. Over expression of Dcyp33 in DrosophilaSL1 cells results in down-regulation of AbdominalB Hoxgene expression, mirroring the effect of human Cyp33 on the expression of human HOXgenes.