Expression of the ZFHEP gene during neurogenensis and myogenesis

ROQUEIRO G; MANAVELLA P; AOKI MP; GEA S; DARLING D; CABANILLAS AM

Congreso; XL Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecula; 2004

Zfhep (Zinc Finger Homeodomain Enhancer-binding Protein) is atranscription factor involved in differentiation processes such asmyogenesis, neurogenesis and lymphopoiesis. The promoter hasbeen recently isolated and so far, there is no direct assessment ofits regulation during cell differentiation. Our goal was to evaluatethe activity of Zfhep promoter during myocyte and neurondevelopment. The embryonal carcinoma (P19) and a mousemyoblast (C2C12) cell lines were differentiated for inducingneurogenesis (by pretreatment with retinoic acid) or myogenesis(by incubation with 2% horse serum), respectively. Western blotand immunocytochemistry methods were used to validate themodel. Human Zfhep promoter was cloned into pGL3-basic andseveral mutant deletions were made. The reporter chimeras andCMVβ-gal (to normalize transfection efficiency) were transfectedinto C2C12 and P19 cells by calcium phosphate and FuGENE6,respectively; then they were induced to differentiate. Luciferaseand β-galactosidase activities were assessed in cell lysates bystandard methods. The promoter was active in all of the constructstested in both, undifferentiated C2C12 and P19 cells. The activityof the Zfhep promoter, decreased significantly after differentiationof P19 to neurons. The activity was also lowered by 30 fold indifferentiated C2C12 cells. These results first show that the Zfhepgene is dynamically regulated during myogenesis and neurogenesis.The repression of the gene could be related to a lack of function ofZfhep during the differentiated cell state.