Proteomic Profiling for Peritoneal Dialysate: Differential Protein Expression in Diabetes Mellitus

Table 2

Subcellular location and protein function of 10 proteins with higher confidence levels identified in peritoneal dialysate of CGN and DM.

Accession no.	Protein name	Subcellular location	Biological process	Molecular function	Protein function
P02768	Albumin (ALB)	Secreted	Cellular response to starvation; Hemolysis by symbiont of host erythrocytes; Maintenance of mitochondrion location	Binding protein	Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca2+, Na+, K+, fatty acids, hormones, bilirubin, and drugs. Its main function is the regulation of the colloidal osmotic pressure of blood. Major zinc transporter in plasma, typically binds about 80% of all plasma zinc.
P02760	Alpha-1-microglobulin/bikunin preproprotein (AMBP)	Secreted	Cell adhesion; Heme catabolic process; Negative regulation of immune response	Serine-type endopeptidase inhibitor activity; Calcium oxalate binding; Small molecule binding; Calcium channel inhibitor activity	Inter-alpha-trypsin inhibitor inhibits trypsin, plasmin, and lysosomal granulocytic elastase. Inhibits calcium oxalate crystallization
P02647	Apolipoprotein A-I (APOA1)	Secreted	Cholesterol metabolism; Lipid metabolism; Lipid transport; Steroid metabolism; Transport	Binding protein	Participates in the reverse transport of cholesterol from tissues to the liver for excretion by promoting cholesterol efflux from tissues and by acting as a cofactor for the lecithin cholesterol acyltransferase (LCAT). As part of the SPAP complex, activates spermatozoa motility.
P01857	Immunoglobulin G1 Fc fragment (IGHG1)	Secreted, membrane	Complement activation, classical pathway; Innate immune response	Antigen binding	G1m marker
P02753	Mutant retinol binding protein (RBP4)	Secreted	Glucose homeostasis; Gluconeogenesis; response to insulin stimulus	Retinol binding; Retinol transporter activity	Delivers retinol from the liver stores to the peripheral tissues. In plasma, the RBP-retinol complex interacts with transthyretin; this prevents its loss by filtration through the kidney glomeruli.
P00738	Haptoglobin alpha2 (HP)	Secreted	Defense response; Metabolic process	Catalytic activity	Haptoglobin combines with free plasma hemoglobin, preventing loss of iron through the kidneys and protecting the kidneys from damage by hemoglobin, while making the hemoglobin accessible to degradative enzymes. Uncleaved haptoglobin, also known as zonulin, plays a role in intestinal permeability, allowing intercellular tight junction disassembly, and controlling the equilibrium between tolerance and immunity to nonself antigens.
P06727	Apolipoprotein A-IV (APOA4)	Secreted	Cholesterol efflux; Cholesterol homeostasis; Cholesterol metabolic process; Chylomicron assembly; Chylomicron remodeling; High-density lipoprotein particle remodeling; Hydrogen peroxide catabolic process; Innate immune response in mucosa; Leukocyte adhesion; Lipoprotein metabolic process; Multicellular organismal lipid catabolic process	Antioxidant activity; Cholesterol transporter activity; Copper ion binding; Phosphatidylcholine binding; Phosphatidylcholine-sterol O-acyltransferase activator activity; Protein homodimerization activity	May have a role in chylomicrons and VLDL secretion and catabolism. Required for efficient activation of lipoprotein lipase by ApoC-II; potent activator of LCAT. Apoa-IV is a major component of HDL and chylomicrons.
P25311	Zn-alpha2-glycoprotein (AZGP1)	Secreted	Antigen processing and presentation; Cell adhesion; Immune response; Lipid catabolic process; Negative regulation of cell proliferation	Fatty acid binding; Protein transmembrane transporter activity; Ribonuclease activity	Stimulates lipid degradation in adipocytes and causes the extensive fat losses associated with some advanced cancers. May bind polyunsaturated fatty acids.
Q04637	Eukaryotic translation initiation factor 4A isoform 1 (EIF4G1)	Cytosol	Cell death; Insulin receptor signaling pathway	DNA binding; Translation initiation factor activity	Component of the protein complex eIF4F, which is involved in the recognition of the mRNA cap, ATP-dependent unwinding of 5′-terminal secondary structure and recruitment of mRNA to the ribosome.
P01892	Human class I histocompatibility antigen (HLA-A)	Golgi membrane; Plasma membrane	Type I interferon-mediated signaling pathway; Regulation of immune response; Interspecies interaction between organisms	Binding protein	Involved in the presentation of foreign antigens to the immune system.