Cancer Research Institute

About: Cancer Research Institute is a nonprofit organization based out in New York, New York, United States. It is known for research contribution in the topics: Cancer & Population. The organization has 1061 authors who have published 754 publications receiving 26712 citations.

How heterologously expressed Escherichia coli genes contribute to understanding DNA repair processes in Saccharomyces cerevisiae.

Abstract: DNA-damaging agents constantly challenge cellular DNA; and efficient DNA repair is therefore essential to maintain genome stability and cell viability. Several DNA repair mechanisms have evolved and these have been shown to be highly conserved from bacteria to man. DNA repair studies were originally initiated in very simple organisms such as Escherichia coli and Saccharomyces cerevisiae, bacteria being the best understood organism to date. As a consequence, bacterial DNA repair genes encoding proteins with well characterized functions have been transferred into higher organisms in order to increase repair capacity, or to complement repair defects, in heterologous cells. While indicating the contribution of these repair functions to protection against the genotoxic effects of DNA-damaging agents, heterologous expression studies also highlighted the role of the DNA lesions that are substrates for such processes. In addition, bacterial DNA repair-like functions could be identified in higher organisms using this approach. We heterologously expressed three well characterized E. coli repair genes in S. cerevisiae cells of different genetic backgrounds: (1) the ada gene encoding O(6)-methylguanine DNA-methyltransferase, a protein involved in the repair of alkylation damage to DNA, (2) the recA gene encoding the main recombinase in E. coli and (3) the nth gene, the product of which (endonuclease III) is responsible for the repair of oxidative base damage. Here, we summarize our results and indicate the possible implications they have for a better understanding of particular DNA repair processes in S. cerevisiae.

A Comparative Protein Profile of Mammalian Erythrocyte Membranes Identified by Mass Spectrometry

Abstract: A comparative analysis of erythrocyte membrane proteins of economically important animals, goat (Capra aegagrus hircus), buffalo (Bubalus bubalis), pig (Sus scrofa), cow (Bos tauras), and human (Homo sapiens) was performed Solubilized erythrocyte membrane proteins were separated by sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE), visualized by staining the gels with Commassie Brilliant Blue (CBB), and identified by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS) Emerging results show that all major erythrocyte membrane proteins present in human are also seen in all the animals except for band 45 which could not be identified Band 3 is seen as more intense and compact, band 41 appears as a doublet in all the animal erythrocyte membranes, band 42 exhibits a slightly higher molecular weight (Mr) in buffalo, and cow and band 49 has a higher Mr in all the animals relative to the human protein In addition, there are two new bands in the goat membrane, band G1, identified as HSP 90α, and band G2 identified as HSP 70 A new band C2 identified as HSP 70 is also seen in cow membranes Peroxiredoxin II is of lower intensity and/or higher Mr in the animals The difference in size of the proteins possibly indicates the variations in the composition of the amino acids The difference in intensity of the proteins among these mammalians highlights the presence of less or more number of copies of that protein per cell This data complement the earlier observations of differences in the sialoglycoprotein profile and effect of proteases and neuraminidase on agglutination among the mammalian erythrocytes This study provides a platform to understand the molecular architecture of the individual erythrocytes, and in turn the dependent disorders, their phylogenetic relationship and also generates a database of erythrocyte membrane proteins of mammals The animals selected for this study are of economic importance as they provide milk for the dairy industry and raw material for leather industry and are routinely sacrificed to obtain non vegetarian food worldwide