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

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.