Analysis of PCBP1, PCBP2, HNRNPK and HNRNPD and its relationship with beta thalassemia.

• Grant number: 12/11664-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2012
• End date: February 28, 2014
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Anderson Ferreira da Cunha
• Grantee: Tainá Regina Damaceno Silveira
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

mRNA turnover is an essential regulatory element of gene expression and is strongly influenced by ribonucleoprotein (RNP) complexes which form on the mRNAs. Studies of human alpha globin mRNA stability have shown a specific RNA complex (alpha complex) formed at the 3' untranslated region of the mRNA thought to regulate the erythrocyte specific accumulation of alpha globin transcript. Poly(C) binding activity is one of the protein activities of this multiprotein complex which consists of two proteins: PCBP1 and PCBP2. Recent studies have identified a second group of protein which is also part of this complex. These proteins are known as HNRNPDs and are also involved in mRNA decay regulated by rich adenine and uracil regions (AREs) being therefore mRNA turnover general factors involved as in mRNA stability as in mRNA decay. In a recent study of global gene expression in cells of beta thalassemic patients we have found PCBP2 and HNRNPK genes, both involved in molecular functions such as chromatin regulation, splicing, transcription and translation, as differentially expressed when compared to controls suggesting a possible regulatory role of these genes in this disease. As the encoded proteins by PCBP1, PCBP2 and HNRNPD are part of the complex mentioned above, our goal is to assess the expression of these genes in reticulocytes of alpha and beta thalassemic patients and to compare its expression with healthy controls using Real Time RT-PCR (qPCR) aiming to establish the role of these proteins in globins genes regulation as well as to better understand the alpha complex and its relationship with thalassemias. Furthermore, we intend to assess the occurrence of polymorphisms or mutations in PCBP2 promoter that could be linked to a potential HNRNPK binding hence regulating PCBP2 expression. These findings significantly can help in the identification of possible therapeutic targets as well as to expand the understanding of the role played by such complex regarding the molecular mechanisms of these disorders.