Identification And Function Analysis Of Proteins Interacted With CTnI

In general,cTnI,an inhibitor subunit of troponin complex,worked as an inhibitors of cross-bridge-ATP enzyme.cTnI could regulate the shrinkage and expansion of myocardial fibers together with other subunits in the Tn complex under the participation of Ca2 + in the cytoplasm.However,this view cannot fully explain why cTnI gene mutations can lead to two different phenotypes of inherited cardiomyopathy,Restrictive cardiomyopathy(RCM)and Hypertrophic cardiomyopathy(HCM).In addition,some researchers found that cTnI could participate in the regulation of chromosome stability with tropomyosin.Therefore,we assume that cTnI may have many unknown biological functions.From the view of Proteomics,one protein cannot accomplish its physiological functions without the interaction with other proteins.Our research was aimed at find more biological function of cTnI in heart disease through the study of cTnI protein interaction network.PART Ⅰ: The identification of the proteins that interacted with cTnI in mice cardiac myocytesObjectiveSeparation and identification of the proteins that interacted with cTnI in mice cardiac myocytes.Methods1)Culture myocardial primary cell from the heart of wild type newborn C57 mice and extract the total protein.2)Employ immune co-precipitationto,isolate the proteins that interacted with cTnI.3)Separation the protein samples by SDS-PAGE gel electrophoresis.4)Send for mass spectrometry after silver nitrate staining.5)Check the results of mass spectrometry in the NCBI protein database and get these gene ID and amino acid sequence.ResultsA total of 262 proteins which may interact with cTnI in physiological condition was identified.ConclusionsIn addition to the cardiac muscle fiber proteins,cTnI could also interact with a variety of functional proteins in physiological condition.PART Ⅱ: Bioinformatics analysis of the proteins interacted with cTnIObjectiveIn order to understand the role of cTnI in the development of heart disease,we analysis the physical and chemical properties and biological function of the proteins got from The first part of our study.Methods1)Get the physical and chemical properties of the proteins by protein analysis software,and predict its transmembrane region and subcellular localization.2)Accomplish the GO enrichment analysis,KEGG Pathway enrichment analysis and the protein interaction network analysis of the proteins by bioinformatics softwares.ResultsWe analyzed the physical and chemical properties of the proteins including the molecular weight,isoelectric point,the average hydrophobicity,and predicted these transmembrane structures and subcellular localizations.the proteins may be involved in ten kinds of biological processes and thirty-three sorts of KEGG biological pathways through the analysis of enrichment.Further more,we get the protein interaction network diagram.ConclusionscTnI could regulate the L-type calcium ion channels,ATP metabolism and the PI3K-Atk signaling pathways with it’s interacted proteins.