Sjl2p is specifically involved in early steps of endocytosis intimately linked to actin dynamics via the Ark1p/Prk1p kinases

• Published in: FEBS letters Vol. 580; no. 2; pp. 633 - 641
• Main Authors: Böttcher, Claudia, Wicky, Sidonie, Schwarz, Heinz, Singer-Krüger, Birgit
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 23-01-2006
• Subjects: Actins - metabolism; Adenosine Triphosphatases - metabolism; Ark1–Prk1 family; Chromatography, Gel; Clathrin; Clathrin - metabolism; Clathrin-Coated Vesicles - metabolism; Cortical actin; Endocytic vesicle; Endocytosis - physiology; Endosomes - metabolism; Fluorescent Dyes - metabolism; Phosphoric Monoester Hydrolases - genetics; Phosphoric Monoester Hydrolases - metabolism; Polyphosphoinositide 5′-phosphatase; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; Pyridinium Compounds - metabolism; Quaternary Ammonium Compounds - metabolism; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; trans-Golgi Network - metabolism; Vesicular Transport Proteins - metabolism; Polyphosphoinositide 5′-phosphatase; Cortical actin; Ark1–Prk1 family; Clathrin; Endocytic vesicle
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2005.12.082

Sjl2p is one of three yeast phosphoinositide 5′-phosphatases that belong to the conserved family of synaptojanins. Here, we show that Sjl2p is specifically associated with cortical actin patches which aggregate upon loss of the actin-regulating kinases Ark1p and Prk1p. The Sjl2p-containing clumps overlap with clathrin and early endocytic structures generated independently of NSF/Sec18p, but not with endosome- and
trans Golgi network-derived membranes. Consistent with the finding that Sjl2p can bind to clathrin heavy chain in vitro, our results suggest that Sjl2p localizes to smooth endocytic vesicles that may be derived from clathrin-coated structures.