Mycobacterium avium inhibits protein kinase C and MARCKS phosphorylation in human cystic fibrosis and non-cystic fibrosis cells

• Published in: PloS one 2024-10, Vol.19 (10), p.e0308299
• Main Authors: Kokesh, Kevin J, Bala, Niharika, Dogan, Yunus E, Nguyen, Van-Anh L, Costa, Marcus, Alli, Abdel
• Format: Article
• Language: English
• Subjects: Alanine; Analysis; Bacteria; Biology and Life Sciences; Care and treatment; Cathepsin B; Cathepsin B - metabolism; Control; Cystic fibrosis; Cystic Fibrosis - metabolism; Cystic Fibrosis - microbiology; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - metabolism; Dehydration; Diagnosis; Epithelial cells; Epithelial Cells - metabolism; Epithelial Cells - microbiology; Epithelium; Health aspects; Humans; Identification and classification; Infections; Intracellular Signaling Peptides and Proteins - metabolism; Kinases; Lungs; MARCKS protein; Mass spectrometry; Mass spectroscopy; Medicine and Health Sciences; Membrane Proteins - metabolism; Membranes; Mycobacterium avium; Mycobacterium avium - metabolism; Myristoylated Alanine-Rich C Kinase Substrate - metabolism; Peptides; Phosphorylation; Physical Sciences; Protein kinase C; Protein Kinase C - metabolism; Protein kinases; Protein transport; Proteins; Proteolysis; Proteomics; Proteomics - methods; Research and Analysis Methods; Respiratory tract infection; Sodium; Sodium conductance; Translocation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0308299

In cystic fibrosis (CF), there is abnormal translocation and function of the cystic fibrosis transmembrane conductance regulator (CFTR) and an upregulation of the epithelial sodium channel (ENaC). This leads to hyperabsorption of sodium and fluid from the airway, dehydrated mucus, and an increased risk of respiratory infections. In this study, we performed a proteomic assessment of differentially regulated proteins from CF and non-CF small airway epithelial cells (SAEC) that are sensitive to Mycobacterium avium. CF SAEC and normal non-CF SAEC were infected with M. avium before the cells were harvested for protein. Protein kinase C (PKC) activity was greater in the CF cells compared to the non-CF cells, but the activity was significantly attenuated in both cell types after infection with M. avium compared to vehicle. Western blot and densitometric analysis showed a significant increase in cathepsin B protein expression in M. avium infected CF cells. Myristoylated alanine rich C-kinase substrate (MARCKS) protein was one of several differentially expressed proteins between the groups that was identified by mass spectrometry-based proteomics. Total MARCKS protein expression was greater in CF cells compared to non-CF cells. Phosphorylation of MARCKS at serine 163 was also greater in CF cells compared to non-CF cells after treating both groups of cells with M. avium. Taken together, MARCKS protein is upregulated in CF cells and there is decreased phosphorylation of the protein due to a decrease in PKC activity and presumably increased cathepsin B mediated proteolysis of the protein after M. avium infection.