title: The role of MPP1/p55 and its palmitoylation in resting state raft organization in HEL cells.
abstract: Here we show the crucial role of MPP1 in lateral membrane ordering/organization in HEL cells (derived from erythroid precursors). Biochemical analyses showed that inhibition of MPP1 palmitoylation or silencing of the MPP1 gene led to a dramatic decrease in the DRM fraction. This was accompanied by a reduction of membrane order as shown by fluorescence-lifetime imaging microscopy (FLIM) analyses. Furthermore, MPP1 knockdown significantly affects the activation of MAP-kinase signaling via raft-dependent RTK (receptor tyrosine kinase) receptors, indicating the importance of MPP1 for lateral membrane organization. In conclusion, palmitoylation of MPP1 appears to be at least one of the mechanisms controlling lateral organization of the erythroid cell membrane. Thus, this study, together with our recent results on erythrocytes, reported elsewhere (Łach et al., J. Biol. Chem., 2012, 287, 18974-18984), points to a new role for MPP1 and presents a novel linkage between membrane raft organization and protein palmitoylation.
authors.affiliation: University of Wrocław, Wrocław, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Biernatowska
authors.forename: Joanna
authors.initials: J
authors.lastname: Podkalicka
authors.forename: Michał
authors.initials: M
authors.lastname: Majkowski
authors.forename: Anita
authors.initials: A
authors.lastname: Hryniewicz-Jankowska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Augoff
authors.forename: Karol
authors.initials: K
authors.lastname: Kozak
authors.forename: Jan
authors.initials: J
authors.lastname: Korzeniewski
authors.forename: Aleksander F
authors.initials: AF
authors.lastname: Sikorski
mesh_terms: D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D041905:Erythroid Cells / Q000378:metabolism*; D006801:Humans; D054878:Lipoylation; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D001798:Blood Proteins; C089465:MPP1 protein, human; D008565:Membrane Proteins; C106354:flotillins; D020928:Mitogen-Activated Protein Kinases