Assortment of phosphatidylinositol 3-kinase complexes--Atg14p directs association of complex I to the pre-autophagosomal structure in Saccharomyces cerevisiae.
In the yeast Saccharomyces cerevisiae, two similar phosphatidylinositol 3-kinase complexes (complexes I and II) function in distinct biological processes, complex I in autophagy and complex II in the vacuolar protein sorting via endosomes. Atg14p is only integrated into complex I, likely facilitating the function of complex I in autophagy. Deletion analysis of Atg14p revealed that N-terminal region containing the coiled-coil structures was essential and sufficient for autophagy. Atg14p localized to pre-autophagosomal structure (PAS) and vacuolar membranes, whereas Vps38p, a component specific to complex II, localized to endosomes and vacuolar membranes. Vps34p and Vps30p, components shared by the two complexes, localized to the PAS, vacuolar membranes, and several punctate structures that included endosomes. The localization of these components to the PAS was Atg14p dependent but not dependent on Vps38p. Conversely, localization of these proteins to endosomes required Vps38p but not Atg14p. Vps15p, regulatory subunit of the Vps34p complexes, localized to the PAS, vacuolar membranes, and punctate structures independent of both Atg14p and Vps38p. Together, these results indicate that complexes I and II function in distinct biological processes by localizing to specific compartments in a manner mediated by specific components of each complex, Atg14p and Vps38p, respectively.
Obara
Keisuke
K
Division of Molecular Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki 444-8585, Japan.
Sekito
Takayuki
T
Ohsumi
Yoshinori
Y
D001343:Autophagy / Q000235:genetics; D000071183:Autophagy-Related Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D010588:Phagosomes / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D058571:Vacuolar Sorting Protein VPS15; D014617:Vacuoles / Q000737:chemistry / Q000378:metabolism; D033921:Vesicular Transport Proteins
D000071183:Autophagy-Related Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D029701:Saccharomyces cerevisiae Proteins; D058571:Vacuolar Sorting Protein VPS15; D033921:Vesicular Transport Proteins; C114337:ATG 14 protein, S cerevisiae; C402377:VPS30 protein, S cerevisiae; C546854:VPS15 protein, S cerevisiae