Evidence for a pool of coronin in mammalian cells that is sensitive to PI 3-kinase.
Coronin, a 57 kDa actin binding protein elutes with an apparent molecular mass of 400-600 kDa from gel filtration columns. This fraction is not unrelated to the reported 200 kDa complex where coronin is associated with phox proteins of the NADPH-oxidase. Phosphatidylinositol 3-kinase (PI 3-kinase) solubilizes coronin from the 400-600 kDa complex, thus constitutive active PI 3-kinase is sufficient to disrupt the complex, whereas wortmannin stabilizes it. Conversely, the phox protein associated pool of coronin is PI 3-kinase independent. During phagocytosis coronin is recruited together with PI 3-kinase to membranes of nascent and early phagosomes co-localizing with the actin cytoskeleton, confirming that coronin contributes to phagocytosis.
Didichenko
S A
SA
Institute for Research in Biomedicine, Bellinzona, Switzerland.
Segal
A W
AW
Thelen
M
M
D000199:Actins / Q000032:analysis; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003599:Cytoskeleton / Q000737:chemistry; D003600:Cytosol / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D010587:Phagocytosis; D010588:Phagosomes / Q000378:metabolism / Q000648:ultrastructure; D019869:Phosphatidylinositol 3-Kinases / Q000032:analysis / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011951:Receptors, Complement / Q000502:physiology; D011961:Receptors, Fc / Q000502:physiology; D000077191:Wortmannin
D000199:Actins; D000730:Androstadienes; D004791:Enzyme Inhibitors; D008840:Microfilament Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011951:Receptors, Complement; D011961:Receptors, Fc; D000077191:Wortmannin; C072061:coronin proteins