Evolutionary diversification of the BetaM interactome acquired through co-option of the ATP1B4 gene in placental mammals

ATP1B4 genes represent a rare instance of orthologous vertebrate gene co-option that radically changed properties of the encoded BetaM proteins, which function as Na, K-ATPase subunits in lower vertebrates and birds. Eutherian BetaM has lost its ancestral function and became a muscle-specific resident of the inner nuclear membrane. Our earlier work implicated BetaM in regulation of gene expression through direct interaction with the transcriptional co-regulator SKIP. To gain insight into evolution of BetaM interactome we performed expanded screening of eutherian and avian cDNA libraries using yeast-two-hybrid and split-ubiquitin systems. The inventory of identified BetaM interactors includes lamina-associated protein LAP-1, myocyte nuclear envelope protein Syne1, BetaM itself, heme oxidases HMOX1 and HMOX2; transcription factor LZIP/CREB3, ERGIC3, PHF3, reticulocalbin-3, and beta-sarcoglycan. No new interactions were found for chicken BetaM and human Na, K-ATPase beta 1, beta 2 and beta 3 isoforms, indicating the uniqueness of eutherian BetaM interactome. Analysis of truncated forms of BetaM indicates that residues 72-98 adjacent to the membrane in nucleoplasmic domain are important for the interaction with SKIP. These findings demonstrate that evolutionary alterations in structural and functional properties of eutherian BetaM proteins are associated with the increase in its interactome complexity

Параоксоназа: универсальный фактор антиоксидантной защиты организма человека

The paraoxonase (PON) gene family includes three members: PON1, PON2, and PON3 aligned in tandem on chromosome 7 in humans. All PON proteins share considerable structural homology and have the capacity to protect cells from oxidative stress; therefore, they have been implicated in the pathogenesis of several inflammatory diseases, particularly atherosclerosis. Increased production of reactive oxygen species as a result of decreased activities of mitochondrial electron transport chain complexes plays a role in the development of many inflammatory diseases, including atherosclerosis. PON1 and PON3 proteins can be detected in plasma and reside in the high-density lipoprotein fraction and protect against oxidative stress by hydrolyzing certain oxidized lipids in lipoproteins, macrophages, and atherosclerotic lesions. Paraoxonase 2 (PON2) possesses antiatherogenic properties and is associated with lower ROS levels. PON2 is involved in the antioxidative and anti-inflammatory response in intestinal epithelial cells. In contrast to PON1 and PON3, PON2 is cell-associated and is not found in plasma. It is widely expressed in a variety of tissues, including the kidney, and protects against cellular oxidative stress. Overexpression of PON2 reduces oxidative status, prevents apoptosis in vascular endothelial cells, and inhibits cell-mediated low density lipoprotein oxidation. PON2 also inhibits the development of atherosclerosis, via mechanisms involving the reduction of oxidative stress. In this review we explore the physiological roles of PON in disease development and modulation of PONs by infective (bacterial, viral) agents.Параоксоназы – это семейство ферментов, представленное PON1, PON2 и PON3, которые обладают широкой специфичностью и каталитической универсальностью. PON1 и PON3 циркулируют в плазме в состоянии, связанном с липопротеинами высокой плотности, предотвращают окисление липропротеинов, уменьшают образование липидных пероксидов и снижают риск развития атеросклероза. PON2 является внутриклеточным ферментом и не обнаруживается в плазме.  PON2 обнаружена во многих тканях организма, включая печень, легкие, трахею, почки, сердце, поджелудочную железу, тонкий кишечник, мышцы, семенники и эндотелиальные клетки. PON2 также присутствует в дофаминергических областях головного мозга и в астроцитах. На субклеточном уровне, PON2 локализуется в митохондриях, где предотвращает накопление триглицеридов и развитие окислительного стресса. PON3 - последняя из открытых параоксоназ обладает более выраженной антиксидантной активностью. PON3 обнаружена в клетках кожи, слюнных железах, железистом эпителии желудка, кишечника, эндометрии, гепатоцитах,  клетках поджелудочной железы, сердце, жировой ткани и в легочном эпителии. PON3 недостаточно изучена, но доказано ее антиоксидантное, противовоспалительное и противомикробное действие  за счет блокирования кворум-зависимых систем бактерий. Избыточная экспрессия PON3 уменьшает образование атеросклеротических бляшек и препятствует развитию ожирения, количество PON3 увеличивается при онкологических заболеваниях, повышая сопротивление опухолевых клеток к оксидативному стрессу и апоптозу. В обзоре представлена информация о физиологической роди параоксоназ, а также их участии в развитии заболеваний, ассоциированных с окислительным стрессом (атеросклероз, эндометриоз, болезнь Паркинсона, цирроз печени, бактериальные и вирусные инфекции и опухолевые процессы)

Proteome-metabolome profiling of ovarian cancer ascites reveals novel components involved in intercellular communication

© 2014 by The American Society for Biochemistry and Molecular Biology, Inc. Ovarian cancer ascites is a native medium for cancer cells that allows investigation of their secretome in a natural environment. This medium is of interest as a promising source of potential biomarkers, and also as a medium for cell-cell communication. The aim of this study was to elucidate specific features of the malignant ascites metabolome and proteome. In order to omit components of the systemic response to ascites formation, we compared malignant ascites with cirrhosis ascites. Metabolome analysis revealed 41 components that differed significantly between malignant and cirrhosis ascites. Most of the identified cancer-specific metabolites are known to be important signaling molecules. Proteomic analysis identified 2096 and 1855 proteins in the ovarian cancer and cirrhosis ascites, respectively; 424 proteins were specific for the malignant ascites. Functional analysis of the proteome demonstrated that the major differences between cirrhosis and malignant ascites were observed for the cluster of spliceosomal proteins. Additionally, we demonstrate that several splicing RNAs were exclusively detected in malignant ascites, where they probably existed within protein complexes. This result was confirmed in vitro using an ovarian cancer cell line. Identification of spliceosomal proteins and RNAs in an extracellular medium is of particular interest; the finding suggests that they might play a role in the communication between cancer cells. In addition, malignant ascites contains a high number of exosomes that are known to play an important role in signal transduction. Thus our study reveals the specific features of malignant ascites that are associated with its function as a medium of intercellular communication