Expression Of Metabolism Related Proteins In Giant Salamander Liver And Analysis On Their Predicted Metabolic Activity

Andrias davidianus is an endangered animal endemic to China.As a primitive amphibian,Andrias davidianus presents a transformation in body structure from aquatic vertebrate to terrestrial vertebrate,which can be of significant importance in scientific studies.At the meantime,Andrias davidianus can provide human body with nutrition and supplement if processed,extracted and purified.Up till now,studies on this animal have been focusing on morphological and anatomical studies as well as molecular genetics,while proteomical studies remain short.Liver is an important organ in living beings,which plays an indispensable part in metabolism,immune system functioning,bile production and secretion,haemopoiesis and blood storage.Cells,especially LHC(Liver hepatocyte),LSEC(Liver sinusoidal endothelial cell),KC(Kupffer cell)and HSC(Hepatic stellate cell)in major,constitute the foundation of liver function.As a newly emerging branch under biology,proteomics has been widely applied in studies in multiple biological fields with the aid of high throughput separation and protein identification.As proteomical study on liver is now a heated topic,Chinese scientists have pioneered in the international project of “human liver proteomics” in which impressive results have been achieved.This project studies normal and healthy livers of Andrias davidianus through the technologies of dimensional electrophoresis,protein spectrum identification,isotope labeling,relative and absolute quantification.It has so far identified 2751 types of protein in an Andrias davidianus liver,establishing a protein expression profile of Andrias davidianus liver.To supplement,data on protein expression abundance has been integrated and analyzed through IPA software and relevant websites,and Andrias davidianus liver proteins are divided into four categories according to different metabolous physiological activities they participate and are listed as follow.(1)Proteins relating to glucose metabolism.A total of 98 types of protein involved in glucose metabolism were found,concerning monosaccharide metabolism,glycogen metabolism,glycoprotein metabolism,glycolipid metabolism,lipopolysaccharide metabolism,glycosaminoglycan metabolism and other glucose metabolism related activities.197 proteinsare known to be functioning in adjusting corresponding physiological activity signals,which include AMPK,HER-2,HIF,p53,PKA andPPAR pathways.(2)Proteins relating to lipid metabolism.122 different types of protein have been recognized in their direct roles in lipid metabolism.Activities concerned are fatty acid metabolism,triglyceride metabolism,phospholipid metabolism,glycolipid metabolism and cholesterol metabolism.185 proteins function in adjusting corresponding physiological activity signals,which include AHR,AMPK,DAR,PKA,PPAR and S1 P pathways.(3)Proteins relating to protein and amino acid metabolism.A total number of 335 different types of proteins are found functioning in metabolism of protein and amino acid.Such activities include metabolism of amino acids and their derivatives,protease functions,lysosomal enzyme functions,proteasome enzyme functions and related courses.Among these proteins,44 are adjusting AHR signal pathways which are responsible for regulating metabolism of protein and amino acid.(4)Proteins relating to nucleotide metabolism.In the process of nucleotide metabolism,188 different types of protein are known to have played their direct parts.These proteins include purine nucleotide metabolism,pyrimidine nucleotide metabolism,DNA metabolism and RNA metabolism.30 proteins including ATM,SAPK/JNK,serotonin receptor are adjusting signal pathways of corresponding physiological activities.The result showed that an Andrias davidianus liver has stronger metabolism activities of glucose and lipid,weaker metabolism activities of protein and amino acid apart from protease and stronger nucleotide metabolism activity.The result shows that function of multiple proteins in Andrias davidianus liver is in accordance with the function of the liver itself,but its liver function differs from that of a higher animal.Therefore the widely held knowledge that an Andrias davidianus is relatively primitive in regards to evolution status is justified in proteomics.