High impact information on PC

• This substantial loss of activity was reconciled with the apparent retention of the integrity of the Ca(2+)-dependent conformation of this mutant by the finding that this Ca(2+)-dependent conformation of [Leu5-->Gln]r-PC interacted poorly with mixed (60:40, w/w) phosphatidylcholine/phosphatidylserine (PL) vesicles [1].
• These represent mitochondria, as PC is known as a mitochondrial enzyme [2].
• Pyruvate carboxylase (EC 6.4.1.1; PC) catalyzes the formation of oxaloacetate by energy-dependent fixation of CO2 to pyruvate [2].
• These results suggest that PC is predominantly an astroglial enzyme and that astroglial cells play an important role in the intermediary and the energy metabolism of the brain [2].
• Inhibition of thrombin bound to cultured bovine aortic endothelial cells (BAEC) by ATIII and the effect of the inhibitor on the activation of PC has been studied using purified components of bovine origin [3].

Biological context of PC

• Expression of PC mRNA is part of the adaptive response to feed intake restriction and is matched by increased capacity for gluconeogenesis from lactate [4].
• Bovine pyruvate carboxylase (PC; EC 6.4.1.1) cDNA was cloned by reverse transcription (RT) PCR [5].
• PC contains 14-16 total Mn2+ binding sites, a value that is reduced to approximately 7-8 in the presence of NaCl [6].
• The data demonstrate increased abundance of PC mRNA during the early transition period followed by increased abundance of PEPCK mRNA during the postpartum period and suggest increased potential metabolism of lactate, pyruvate, and amino acids that contribute to the liver pyruvate pool [7].
• Northern analysis of RNA from liver biopsy samples obtained on days -28, -14, +1, +28, and +56 relative to calving indicated that PC and PEPCK mRNA expression were responsive to onset of lactation but not to prepartum protein or RUP concentration [7].

Anatomical context of PC

• A 2.8-fold increase in the consumption of oxygen was observed in the PC 12 treated spermatozoa in the presence of the 3 combined substrates (pyruvate-lactate-glucose) [8].
• Colostrum feeding increased (P < 0.05) mitochondrial PEPCK mRNA levels and PEPCK activities in calves not treated with DEXA but decreased (P < 0.1) amounts of PC mRNA [9].
• This study demonstrates that PC is a potent ABTS(*)(+) scavenger even when bound to protein and that the complexes may act as a radical sink within the gastrointestinal tract [10].
• The oxidative energy requirements of bovine spermatozoa capacitated with dilauroil-phosphatidylcholine liposomes (PC 12) and the effect of these liposomes on acrosome reaction necessary for in vitro fertilization were studied [8].
• Protac may be suitable as an activator of PC in bovine and equine plasmas; however, it appears ineffective in generating anticoagulant activity in canine plasma [11].

Associations of PC with chemical compounds

• Liver biopsy samples collected on d 5 and 10 were used for PC mRNA, PEPCK mRNA, and in vitro measure of gluconeogenesis from radiolabelled propionate and lactate [4].
• Feed restriction induces pyruvate carboxylase but not phosphoenolpyruvate carboxykinase in dairy cows [4].
• Upon removal of a 41-residue peptide from the amino terminus of the light chain of PC, and, concomitantly, all of the gamma-carboxyglutamic acid residues, the resulting protein, GDPC, possesses a single Mn2+ site of Kd = 120 +/- 20 microM [6].
• We have tested whether a high-glucocorticoid status after birth, as well as colostrum feeding, influences glucose metabolism in association with changes of hepatic expression and activities of gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) and pyruvate carboxylase (PC; EC 6.4.1.1) in neonatal calves [9].
• Dexamethasone treatment decreased hepatic mRNA levels and activities of PC (P < 0.001 and P < 0.10) and activities of PEPCK (P < 0.001) but increased (P < 0.001) the glycogen content [9].

Regulatory relationships of PC

• This sequence is identical to that contained in the tetradecapeptide released from bovine protein C (PC) as a result of its conversion to its activated form (APC), except that Phe13 replaced the normal Pro13, in order to discourage cross-reactivity of antibodies to the carboxylterminal portion of APep with PC [12].

Other interactions of PC

• High-affinity binding of proteolytic active thrombin to thrombomodulin at the cell surface effectively facilitates the activation of the potent anticoagulant protein C (PC) [3].
• The antibody pool obtained reacted with PC and showed virtually no cross-reactivity toward either APC or several typical plasma proteins [12].
• Short-term bST treatment had no detectable effects on contents of PC, PEPCK, and MTP mRNA in the liver [13].
• Expression of PEPCK and IGF-I mRNA were increased with ST but PC mRNA was unchanged [14].
• Liver biopsies were obtained on d -28, -14, 1, 28, and 56 relative to calving, and the abundances of AS, OTC, PC, PEPCK, and 18S mRNA were determined by Northern blot analysis of total RNA [15].

Analytical, diagnostic and therapeutic context of PC

• Peptide mapping and microsequencing identify this protein as pyruvate carboxylase (PC), an abundant mitochondrial enzyme [16].
• The anti-Id MAb were shown by ELISA to be specific for PC-binding proteins of VH1/V kappa 24 H and L chains of various isotypes [17].
• By immunoblotting and microsequence analysis, this protein was identified as pyruvate carboxylase (PC), an abundant mitochondrial enzyme [18].
• Gel electrophoresis of SDS-solubilized biotin-containing membranes, followed by Western blot analysis using avidin-linked peroxidase, resulted in three stained bands with molecular weights similar to those of the mitochondrial carboxylases: propionyl carboxylase, methylmalonyl carboxylase, and pyruvate carboxylase [19].

References