Low molecular weight tyrosine phosphatase (PTP-LMW) activity profile in different stages of osteoblast growth cultures

• Grant number: 06/04620-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2006
• End date: November 30, 2007
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Pietro Ciancaglini
• Grantee: Ricardo Melo Neves
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Events as phosphorylation and dephosphorylation of tyrosine residues in proteins have been shown as decisive in the regulation of division, differentiation and cellular development. Despite the current structural and kinetic knowledge of low molecular weight phosphatase Tyrosine proteins (PTPs-BMr) and its unequivocal importance, few controlled cellular systems (in vitro) were used to evaluate the physiological role of this PTPs class.Osteoblasts are cells which are capable of producing and mineralizing an organic matrix primarily constituted by type I collagen (95%), growth factors and other non collagen proteins. These cells present marking proliferative and differentiation phase, being an interesting model to study the PTP-BMr profile during osteogenesis. The osteoblasts interaction with different surfaces has been recognized as a key event on the activation / deactivation of many genes.Hence, the objective of this work is to determine, in vitro, the expression profile and activity of the PTP-BMr in osteoblasts primary culture. The positive hypothesis of this study is that the modulation of the activity of PTP-BMr occurs during different stages of cellular development and mineralization. This project will be developed in cooperation with the research group linked to the FAPESP thematic (03/09767-0, in progress), coordinated by Prof. Dr. Adalberto Luiz Rosa (FORP-USP) and with the support of Prof. Dr. José Mauro Granjeiro (UFF-RJ).