Phosphorylation Controls Autoinhibition of Cytoplasmic Linker Protein-170

HS Lee, YA Komarova, ES Nadezhdina, R Anjum, JG Peloquin, JM Schober, O Danciu, J van Haren, Niels Galjart, SP Gygi, Anna Akhmanova, GG Borisy

Research output: Contribution to journalArticleAcademicpeer-review

35 Citations (Scopus)

Abstract

Cytoplasmic linker protein (CLIP)-170 is a microtubule (MT) plus-end-tracking protein that regulates MT dynamics and links MT plus ends to different intracellular structures. We have shown previously that intramolecular association between the N and C termini results in autoinhibition of CLIP-170, thus altering its binding to MTs and the dynactin subunit p150(Glued) (J. Cell Biol. 2004: 166, 1003-1014). In this study, we demonstrate that conformational changes in CLIP-170 are regulated by phosphorylation that enhances the affinity between the N- and C-terminal domains. By using site-directed mutagenesis and phosphoproteomic analysis, we mapped the phosphorylation sites in the third serine-rich region of CLIP-170. A phosphorylation-deficient mutant of CLIP-170 displays an "open" conformation and a higher binding affinity for growing MT ends and p150(Glued) as compared with nonmutated protein, whereas a phosphomimetic mutant confined to the "folded back" conformation shows decreased MT association and does not interact with p150(Glued). We conclude that phosphorylation regulates CLIP-170 conformational changes resulting in its autoinhibition.
Original languageUndefined/Unknown
Pages (from-to)2661-2673
Number of pages13
JournalMolecular Biology of the Cell
Volume21
Issue number15
DOIs
Publication statusPublished - 2010

Cite this