Sox family proteins are characterized by a unique DNA-binding domain, a HMG
box which shows at least 50% sequence similarity with mouse Sry, the sex-d
etermining factor. At present almost 30 Sox genes have been identified, Mem
bers of this family have been shown to be conserved during evolution and to
play key roles during animal development. Some are involved in human disea
ses, including sex reversal. Here we report the isolation of a novel member
of the Sox gene family, Sox30, which may constitute a distinct subgroup of
this family, Using a bacterially expressed DNA-binding domain of Sox30, we
show that it is able to specifically recognize the ACAAT motif. Furthermor
e, Sox30 is capable of activating transcription from a synthetic promoter c
ontaining the ACAAT motif. The specific expression of Sox30 in normal teste
s, but not in maturing germ cell-deficient testes, suggests the involvement
of Sox30 in differentiation of male germ cells. Mapping analyses revealed
that the Sox30 gene is located on human chromosome 5 (5q33) and on mouse ch
romosome 11.