title: Involvement of myosin VI immunoanalog in pinocytosis and phagocytosis in Amoeba proteus.
abstract: Recently, we found a 130-kDa myosin VI immunoanalog in amoeba, which bound to actin in an ATP-sensitive manner and in migrating amoebae colocalized to filamentous actin and dynamin II-containing vesicular structures. To further characterize this protein, we assessed its involvement in amoeba pinocytosis and phagocytosis. Confocal immunofluorescence microscopy and electron microscopy of immunogold-stained cells revealed that, in pinocytotic and phagocytotic amoebae, the myosin VI immunoanalog was visible throughout the cells, including pinocytotic channels and pinocytotic vesicles as well as phagosomes and emerging phagocytic cups. Blocking endogenous protein with anti-porcine myosin VI antibody (introduced into cells by means of microinjection) caused severe defects in pinocytosis and phagocytosis. In comparison with control cells, the treated amoebae formed ~75% less pinocytotic channels and phagocytosed ~65% less Tetrahymena cells. These data indicate that the myosin VI immunoanalog has an important role in pinocytosis and phagocytosis in Amoeba proteus (Pal.).
authors.affiliation: Department of Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur Street, Warsaw 02-093, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sobczak
authors.forename: Anna
authors.initials: A
authors.lastname: Wasik
authors.forename: Wanda
authors.initials: W
authors.lastname: Kłopocka
authors.forename: Maria Jolanta
authors.initials: MJ
authors.lastname: Redowicz
mesh_terms: D000656:Amoeba / Q000166:cytology / Q000502:physiology*; D000818:Animals; D007150:Immunohistochemistry; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis / Q000502:physiology*; D010873:Pinocytosis / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D034421:Sus scrofa
chemical_list: D020033:Protein Isoforms; C089785:myosin VI; D018995:Myosin Heavy Chains