Regulation of flagellar dynein by phosphorylation of a 138-kD inner arm dynein intermediate chain

• Published in: The Journal of cell biology Vol. 136; no. 1; pp. 167 - 176
• Main Authors: Habermacher, G. (Emory University School of Medicine, Atlanta, GA.), Sale, W.S
• Format: Journal Article
• Language: English
• Published: United States Rockefeller University Press 13.01.1997; The Rockefeller University Press
• Subjects: Amino Acid Sequence; Animals; Arm; Carrier Proteins - pharmacology; Cell motility; Cells; Cellular biology; Chlamydomonas; CHLAMYDOMONAS REINHARDTII; Chlamydomonas reinhardtii - cytology; Dyneins - genetics; Dyneins - isolation & purification; Dyneins - metabolism; Enzyme Inhibitors - pharmacology; ESTRUCTURA CELULAR; Flagella; Flagella - metabolism; Flagella - physiology; FOSFOPROTEINAS; FOSFORILACION; Freshwater; Fungi; Gels; Gene expression regulation; HIDROLASAS; HYDROLASE; Intracellular Signaling Peptides and Proteins; Marine Toxins; Microcystins; Microtubules; Microtubules - physiology; Molecular Sequence Data; Peptide Fragments - pharmacology; Peptides, Cyclic - pharmacology; Phosphatases; Phosphoprotein Phosphatases - antagonists & inhibitors; PHOSPHOPROTEINE; Phosphoproteins; Phosphoproteins - metabolism; PHOSPHORYLATION; Physiological regulation; Protein Kinase Inhibitors; PROTEINA QUINASA; PROTEINE KINASE; Proteins; REACCIONES QUIMICAS; REACTION CHIMIQUE; STRUCTURE CELLULAIRE
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.136.1.167

One of the challenges in understanding ciliary and flagellar motility is determining the mechanisms that locally regulate dynein-driven microtubule sliding. Our recent studies demonstrated that microtubule sliding, in Chlamydomonas flagella, is regulated by phosphorylation. However, the regulatory proteins remain unknown. Here we identify the 138-kD intermediate chain of inner arm dynein I1 as the critical phosphoprotein required for regulation of motility. This conclusion is founded on the results of three different experimental approaches. First, genetic analysis and functional assays revealed that regulation of microtubule sliding, by phosphorylation, requires inner arm dynein I1. Second, in vitro phosphorylation indicated the 138-kD intermediate chain of I1 is the only phosphorylated subunit. Third, in vitro reconstitution demonstrated that phosphorylation and dephosphorylation of the 138-kD intermediate chain inhibits and restores wild-type microtubule sliding, respectively. We conclude that change in phosphorylation of the 138-kD intermediate chain of I1 regulates dynein-driven microtubule sliding. Moreover, based on these and other data, we predict that regulation of I1 activity is involved in modulation of flagellar waveform