Arabidopsis phosphatidylinositol phosphate kinase 1 binds F-actin and recruits phosphatidylinositol 4-kinase beta1 to the actin cytoskeleton.
The actin cytoskeleton can be influenced by phospholipids and lipid-modifying enzymes. In animals the phosphatidylinositol phosphate kinases (PIPKs) are associated with the cytoskeleton through a scaffold of proteins; however, in plants such an interaction was not clear. Our approach was to determine which of the plant PIPKs interact with actin and determine whether the PIPK-actin interaction is direct. Our results indicate that AtPIPK1 interacts directly with actin and that the binding is mediated through a predicted linker region in the lipid kinase. AtPIPK1 also recruits AtPI4Kbeta1 to the cytoskeleton. Recruitment of AtPI4Kbeta1 to F-actin was dependent on the C-terminal catalytic domain of phosphatidylinositol-4-phosphate 5-kinase but did not require the presence of the N-terminal 251 amino acids, which includes 7 putative membrane occupation and recognition nexus motifs. In vivo studies confirm the interaction of plant lipid kinases with the cytoskeleton and suggest a role for actin in targeting PIPKs to the membrane.
Davis
Amanda J
AJ
Plant Biology, North Carolina State University, Raleigh, NC 27695, USA.
Im
Yang Ju
YJ
Dubin
Joshua S
JS
Tomer
Kenneth B
KB
Boss
Wendy F
WF
D019870:1-Phosphatidylinositol 4-Kinase / Q000235:genetics / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D013058:Mass Spectrometry; D018129:Phosphatidylinositol Phosphates; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D000199:Actins; D029681:Arabidopsis Proteins; D018129:Phosphatidylinositol Phosphates; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D017853:Phosphotransferases (Alcohol Group Acceptor); D019870:1-Phosphatidylinositol 4-Kinase; C020077:1-phosphatidylinositol-4-phosphate 5-kinase; C502534:PIPK10 protein, Arabidopsis