Disease relevance of Pctp

• Transient transfection of a series of 5'-deleted Pctp-promoter-firefly luciferase constructs into Reuber H35 rat hepatoma cells, which express Pctp mRNA, and Gunn rat fibroblasts, which do not, suggest that cis-acting elements in a 637bp promoter region contribute to enhanced expression of PC-TP in liver [1].
• These results demonstrate the utility of baculovirus for expressing recombinant phosphatidylcholine transfer protein and should facilitate studies designed to elucidate the structural biology and physiological functions of this uniquely specific phospholipid transfer protein [2].

High impact information on Pctp

• The substrate for the inositol phosphate-regulated protein kinase was identified as a phosphatidylcholine transfer protein-like protein [3].
• The kinetics of the PCTP-mediated exchange process indicate that the t1/2 of the transmembrane movement at 30 degrees C is 2 min or less [4].
• Although postulated to participate in phosphatidylcholine biosynthesis and biliary trafficking in liver, the molecular basis underlying the substrate specificity of phosphatidylcholine transfer protein remains to be elucidated [2].
• When assayed in vitro, cytosol of recombinant but not control infected cells demonstrated high levels of intermembrane phosphatidylcholine transfer activity and no transfer activity for phosphatidylethanolamine [2].
• Partially purified phosphatidylcholine transfer protein from rat liver transfers phosphatidylcholine and phosphatidyl-PDME at identical rates but transfers phosphatidylethanolamine at a rate too low to be detected [5].

Biological context of Pctp

• No sequence homologies were noted between any of these small molecular weight cytosolic proteins and nonspecific lipid transfer protein (sterol carrier protein 2), phosphatidylcholine transfer protein, serum albumin or apolipoprotein AI [6].
• Tissue distribution and subcellular localization of phosphatidylcholine transfer protein in rats as determined by radioimmunoassay [7].

Anatomical context of Pctp

• Results of experiments using phosphatidylcholine transfer protein and phospholipase C as probes indicate that there are at least two pools of phosphatidylcholine in rat liver microsomes [8].
• The phosphatidylcholine transfer from macrophages to lymphocytes was then investigated [9].
• Vitamin D metabolites stimulate phosphatidylcholine transfer to renal brush-border membranes [10].
• The phosphatidylcholine-transfer protein catalyzed import of phosphatidylcholine into isolated rat liver mitochondria [11].
• The site of sphingomyelin synthesis in the rapidly growing Morris hepatomas 7777 and 5123D was determined by incubating plasma membrane, mitochondrial and microsomal membrane fractions with vesicles of phosphatidyl[methyl-14C]choline in the presence of phosphatidylcholine transfer protein [12].

Associations of Pctp with chemical compounds

• The transfer of phosphatidylinositol from rat liver microsomes to liposomes stimulated by cytoplasmic protein was found to be inhibited by the addition of chlorpromazine, while the phosphatidylcholine transfer was not affected [13].
• Phosphatidylcholine transfer protein was labelled with 125I by the glucose oxidase-lactoperoxidase method and purified from the reaction mixture by affinity chromatography [14].
• Phosphatidylcholine exchange between liposomes and mitochondria catalyzed by rat liver phosphatidylcholine transfer protein is strongly stimulated by N-ethylmaleimide (NEM) when PC/PI (molar ratio, 4:1) donor liposomes are used [15].
• Although the protein preferentially transfers dipalmitoylphosphatidylcholine, the incorporation of increasing mole percentages of dipalmitoylphosphatidylcholine into unilamellar phosphatidylcholine vesicles profoundly affects their effectiveness as donors for phosphatidylcholine transfer by the transfer protein [16].

Analytical, diagnostic and therapeutic context of Pctp

• Phosphatidylcholine transfer protein from rat liver: purification and radioimmunoassay [17].

References