Characterization of the human TCAM1P pseudogene and its activation by a potential dual promoter-enhancer: comparison with a protein-coding mouse orthologue.

ABSTRACT

TCAM1P is a unitary pseudogene, which was disabled since the human-mouse divergence. Here we found that TCAM1P was specifically expressed in the human testis, with different cell type-specificity from mouse Tcam1, and characterized its transcripts. At the mouse locus, a multifunctional dual promoter-enhancer (DPE) controls the expression of Tcam1 and Smarcd2 genes. The corresponding human sequence was found to potentially function as a DPE, although the molecular mechanism was different from mouse. Interestingly, the change in DPE activity occurred before pseudogenization of TCAM1P. These data suggest the presence of a DPE in the human genome for the first time, and provide an important model of evolutionary changes in the regulatory mechanism of a pseudogene.