Og. Opitz et Ak. Rustgi, Interaction between Sp1 and cell cycle regulatory proteins is important intransactivation of a differentiation-related gene, CANCER RES, 60(11), 2000, pp. 2825-2830
The stratified squamous epithelium is a model system in which to define mol
ecular mechanisms underlying the switch from proliferation to differentiati
on. This can be achieved through the functional dissection of keratin gene
promoters, Having previously established the importance of keratin 4 in mai
ntaining the differentiated phenotype in corneal epithelial cells, we inves
tigated the role of Sp1-mediated transactivation of the keratin 4 promoter
given the role of Sp1 in differentiation and fell cycle progression. Sp1 tr
ansactivation of the keratin 4 promoter was diminished in cyclin D1-overexp
ressing cells, which may be mediated through a newly described direct inter
action between Sp1 and cyclin D1 and opposed by a complex between Sp1 and p
RB.