title: Identification of the surfactant protein A receptor 210 as the unconventional myosin 18A.
abstract: Mass spectrometric characterization of the surfactant protein A (SP-A) receptor 210 (SP-R210) led to the identification of myosin (Myo) XVIIIA and nonmuscle myosin IIA. Antibodies generated against the unique C-terminal tail of MyoXVIIIA revealed that MyoXVIIIA, MyoIIA, and SP-R210 have overlapping tissue distribution, all being highly expressed in myeloid cells, bone marrow, spleen, lymph nodes, and lung. Western blot analysis of COS-1 cells stably transfected with either MyoXVIIIA or MyoIIA indicated that SP-R210 antibodies recognize MyoXVIIIA. Furthermore, MyoXVIIIA but not MyoIIA localized to the surface of COS-1 cells, and most importantly, expression of MyoXVIIIA in COS-1 cells conferred SP-A binding. Western analysis of recombinant MyoXVIIIA domains expressed in bacteria mapped the epitopes of previously derived SP-R210 antibodies to the neck region of MyoXVIIIA. Antibodies raised against the neck domain of MyoXVIIIA blocked the binding of SP-A to macrophages. Together, these findings indicate that MyoXVIIIA constitutes a novel receptor for SP-A.
authors.affiliation: Center of Biomedical Research, University of Texas Health Center, Tyler, Texas 75708-3154, USA.
authors.forename: Ching-Hui
authors.initials: CH
authors.lastname: Yang
authors.forename: Jacek
authors.initials: J
authors.lastname: Szeliga
authors.forename: Jeremy
authors.initials: J
authors.lastname: Jordan
authors.forename: Shawn
authors.initials: S
authors.lastname: Faske
authors.forename: Zvjezdana
authors.initials: Z
authors.lastname: Sever-Chroneos
authors.forename: Bre
authors.initials: B
authors.lastname: Dorsett
authors.forename: Robert E
authors.initials: RE
authors.lastname: Christian
authors.forename: Robert E
authors.initials: RE
authors.lastname: Settlage
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Shabanowitz
authors.forename: Donald F
authors.initials: DF
authors.lastname: Hunt
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Whitsett
authors.forename: Zissis C
authors.initials: ZC
authors.lastname: Chroneos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000939:Epitopes / Q000737:chemistry; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000737:chemistry; D047468:Immunoprecipitation; D008264:Macrophages / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009218:Myosins / Q000737:chemistry* / Q000502:physiology; D024507:Nonmuscle Myosin Type IIA / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D037662:Pulmonary Surfactant-Associated Protein A / Q000737:chemistry; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014018:Tissue Distribution; D014162:Transfection; D020298:U937 Cells
chemical_list: D018076:DNA, Complementary; D000939:Epitopes; D007074:Immunoglobulin G; D009218:Myosins; D024507:Nonmuscle Myosin Type IIA; D010455:Peptides; D020033:Protein Isoforms; D037662:Pulmonary Surfactant-Associated Protein A; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C067774:surfactant protein A receptor; C407152:MYO18A protein, human