Identification of the surfactant protein A receptor 210 as the unconventional myosin 18A.
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.
Yang
Ching-Hui
CH
Center of Biomedical Research, University of Texas Health Center, Tyler, Texas 75708-3154, USA.
Szeliga
Jacek
J
Jordan
Jeremy
J
Faske
Shawn
S
Sever-Chroneos
Zvjezdana
Z
Dorsett
Bre
B
Christian
Robert E
RE
Settlage
Robert E
RE
Shabanowitz
Jeffrey
J
Hunt
Donald F
DF
Whitsett
Jeffrey A
JA
Chroneos
Zissis C
ZC
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
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