Testing the interactions between the telomeric proteins LaRbp38 and LaRPA-1 using the yeast two-hybrid system

• Grant number: 11/22879-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: December 31, 2012
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Maria Isabel Nogueira Cano
• Grantee: Douglas Diez Gonçalves
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Testing the interactions between the telomeric proteins LaRbp38 and LaRPA-1 using the yeast two-hybrid system Leishmaniasis is a group of infectious diseases caused by parasites of the genus Leishmania, which affect millions of people around the world, with two million new cases and 70,000 deaths each year. Drugs used to treat different clinical forms of the disease have high toxicity and low efficacy, in addition to causing many side effects. Moreover, the emergence of resistant parasites and vectors argues in favor of the development of new therapies to eradicate the disease, which is largely encouraged by the World Health Organization. Thus, a better understanding of the molecular biology of these protozoa may facilitate these discoveries. Actually, telomeres, the nucleoprotein structures at the ends of eukaryotic chromosomes, have been the subject of intensive studies, since they are been considered potential therapeutic targets against malignant tumors and pathogenic microorganisms. Telomeres typically appear as dynamic structures where interactions between DNA and proteins result in the formation of a high-order telomeric complex, responsible for the protection and maintenance of chromosomes and genome stability and subsequently cell viability. Components of the Leishmania amazonensis telomeric complex were identified using different biochemical approaches. Among them were identified LaRPA-1 (L. amazonensis Replication Protein A-1) and LaRbp38 (L. amazonensis RNA binding protein) which showed the ability to interact with telomeric DNA in vitro and in vivo. More recently, we were able to show by immunoprecipitation and "pull-down" assays, that these proteins are part of a common complex at parasite telomeres. This work aims to confirm these possible interactions, using an in vivo assay, known as the yeast two-hybrid system. One of our main objectives is to standardize the method in our laboratory since it will allow confirming in a feasible manner, most of the protein: protein interactions that we are testing in the lab. To facilitate the analysis of the results and unequivocally check the interactions and differentiate them from auto-activation and false positive, both proteins (LaRPA-1 and LaRbp38) will be tested individually and as bait (fused to the DNA binding domain of LexA) and prey (fused to the GAL4 activation domain).(AU)