A quantitative proteomic analysis of cofilin phosphorylation in myeloid cells and its modulation using the LIM kinase inhibitor Pyr1

• Published in: PloS one 2018-12, Vol.13 (12), p.e0208979-e0208979
• Main Authors: Prudent, Renaud, Demoncheaux, Nathalie, Diemer, Hélène, Collin-Faure, Véronique, Kapur, Reuben, Paublant, Fabrice, Lafanechère, Laurence, Cianférani, Sarah, Rabilloud, Thierry
• Format: Article
• Language: English
• Subjects: Actin; Actin Depolymerizing Factors - chemistry; Actin Depolymerizing Factors - metabolism; Actins - metabolism; Amino Acid Sequence; Binding energy; Binding Sites; Biochemistry, Molecular Biology; Biology; Biology and Life Sciences; Breast cancer; Cancer; Cancer treatment; Carbazoles - pharmacology; Cell culture; Cell Line; Cellular signal transduction; Cofilin; Cytoskeleton; Deregulation; Enzyme inhibitors; Genomics; Human evolution; Humans; Inhibition; Kinase inhibitors; Kinases; Leukemia; Life Sciences; LIM kinase; Lim Kinases - antagonists & inhibitors; Metastasis; Microtubules; Muscle proteins; Myeloid cells; Myeloid Cells - drug effects; Myeloid Cells - metabolism; Pharmacology; Phenols (Class of compounds); Phosphorylation; Phosphorylation - drug effects; Physical Sciences; Protein Kinase Inhibitors - pharmacology; Proteins; Proteomics; Regulation; Research and Analysis Methods; Serine; Substrates; Threonine; Tumor cell lines; Tumors; Tyrosine
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0208979

LIM kinases are located at a strategic crossroad, downstream of several signaling pathways and upstream of effectors such as microtubules and the actin cytoskeleton. Cofilin is the only LIM kinases substrate that is well described to date, and its phosphorylation on serine 3 by LIM kinases controls cofilin actin-severing activity. Consequently, LIM kinases inhibition leads to actin cytoskeleton disorganization and blockade of cell motility, which makes this strategy attractive in anticancer treatments. LIMK has also been reported to be involved in pathways that are deregulated in hematologic malignancies, with little information regarding cofilin phosphorylation status. We have used proteomic approaches to investigate quantitatively and in detail the phosphorylation status of cofilin in myeloid tumor cell lines of murine and human origin. Our results show that under standard conditions, only a small fraction (10 to 30% depending on the cell line) of cofilin is phosphorylated (including serine 3 phosphorylation). In addition, after a pharmacological inhibition of LIM kinases, a residual cofilin phosphorylation is observed on serine 3. Interestingly, this 2D gel based proteomic study identified new phosphorylation sites on cofilin, such as threonine 63, tyrosine 82 and serine 108.