%0 Journal Article
%T Comparative analyses of the Conserved Oligomeric Golgi (COG) complex in vertebrates
%A Rita Quental
%A Lu¨ªsa Azevedo
%A Rune Matthiesen
%A Ant¨®nio Amorim
%J BMC Evolutionary Biology
%D 2010
%I BioMed Central
%R 10.1186/1471-2148-10-212
%X We used protein distances and dN/dS ratios as a measure of the rate of proteins evolution. The results showed that all COG subunits are evolving under strong purifying selection, although COG1 seems to evolve faster than the remaining proteins. In addition, we also tested the expression of COG genes in 20 human tissues, and demonstrate their ubiquitous nature.COG complex has a critical role in Golgi structure and function, which, in turn, is involved in protein sorting and glycosylation. The results of this study suggest that COG subunits are evolutionary constrained to maintain the interactions between each other, as well with other partners involved in vesicular trafficking, in order to preserve both the integrity and function of the complex.Most cellular processes are carried out by multiprotein complexes that constitute important functional units in the cell [1]. This fact has motivated a number of studies aiming to investigate the structure, function and evolution of such multisubunit molecular machines [e.g., [1-4]].A cellular process in which protein complexes are known to be involved is the transport of proteins between cellular compartments (vesicular trafficking) [5,6]. Proteins synthesised in the secretory pathway are transported inside vesicles that move from the endoplasmic reticulum to the Golgi apparatus, from where polypeptides are then sorted to several cellular compartments [7]. As progression through the Golgi occurs, proteins may undergo modifications like glycosylation, a necessary step for their stability and function [8]. Several large protein complexes play an important role in the fidelity of vesicle fusion, acting as tethering factors through the formation of physical links between membranes prior to fusion [5,6,9]. One of these is the Conserved Oligomeric Golgi (COG) complex [10], which localizes at the cytoplasmic surface of the Golgi apparatus [11-14].Several studies have been performed demonstrating the involvement of COG in retrograde
%U http://www.biomedcentral.com/1471-2148/10/212