Otero A, Bustelo X R, Pichel J G, Freire M, Gómez-Márquez J
Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago, Santiago de Compostela, La Coruña, Spain.
Biochim Biophys Acta. 1993 Mar 10;1176(1-2):59-63. doi: 10.1016/0167-4889(93)90177-q.
Thymosin beta 4 (beta 4) is an ubiquitous 5-kDa peptide that has been identified as an actin-sequestering peptide. In this work, Northern blot analysis was used to study the beta 4 mRNA levels during the cell cycle of rat thymocytes and hepatocytes as well as in human lymphocytes from patients with leukemia. beta 4 mRNA was found in all the stages of thymocyte and hepatocyte cell cycle, showing an increase in the S-phase which was maintained during the G2 and M phases. Incubation of splenic T-cells with concanavalin A, phorbol myristate acetate or the ionophore A23187 lead to a similar increase of beta 4 transcript during the S-phase. The increase in beta 4 mRNA observed in the G2/M boundary of the cell cycle, together with its ability to inhibit actin polymerization, suggests a possible role of beta 4 in the the morphological changes and actin redistribution occurring during the cytokinesis.
