Functional interaction of Azotobacter vinelandii cytoplasmic cyclophilin with the biotin carboxylase subunit of acetyl-CoA carboxylase

• Published in: Biochemical and biophysical research communications Vol. 424; no. 4; pp. 736 - 739
• Main Authors: Dimou, Maria, Zografou, Chrysoula, Venieraki, Anastasia, Katinakis, Panagiotis
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10.08.2012
• Subjects: Acetyl-CoA carboxylase; Acetyl-CoA Carboxylase - metabolism; Adenosine Triphosphate - metabolism; Azotobacter vinelandii - enzymology; Bacterial Proteins - metabolism; Biotin carboxylase; Carbon-Nitrogen Ligases - metabolism; Cyclophilin; Cyclophilins - metabolism; Cytoplasm - enzymology; Hydrolysis; Peptidyl-prolyl cis/trans isomerase; Protein interaction; CoA; Acetyl-CoA carboxylase; Cyclophilin; PPIase; Biotin carboxylase; Peptidyl-prolyl cis/trans isomerase; Protein interaction
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.07.021

► The cytoplasmic cyclophilin AvppiB binds the biotin carboxylase AvaccC. ► The PPIase active site of AvppiB although involved is not essential for the binding. ► AvppiB significantly influences the ATP hydrolyzing activity of AvaccC. ► PPIase activity of AvppiB negatively regulates the AvppiB mediated enhancement of AvaccC activity. Cyclophilins (E.C. 5.1.2.8) are protein chaperones with peptidyl-prolyl cis/trans isomerase activity (PPIase). In the present study, we demonstrate a physical interaction among AvppiB, encoding the cytoplasmic cyclophilin from the soil nitrogen-fixing bacterium Azotobacter vinelandii, and AvaccC, encoding the biotin carboxylase subunit of acetyl-CoA carboxylase, which catalyzes the committed step in long-chain fatty acid synthesis. A decrease in AvppiB PPIase activity, in the presence of AvaccC, further confirms the interaction. However, PPIase activity seems not to be essential for these interactions since a PPIase active site mutant of cyclophilin does not abolish the AvaccC binding. We further show that the presence of cyclophilin largely influences the measured ATP hydrolyzing activity of AvaccA in a way that is negatively regulated by the PPIase activity. Taken together, our data support a novel role for cyclophilin in regulating biotin carboxylase activity.