title: Immunohistochemical studies on the distribution of cellular myosin II isoforms in brain and aorta.
abstract: The distribution of nonmuscle myosin isoforms in brain and aorta was studied by using polyclonal antibodies against two synthetic peptides selected from a region near the carboxyl terminus of bovine brain (peptide IIB) and human macrophage (peptide IIA) myosin. Immunoblots of brain homogenates and purified myosin showed two major bands stained by anti-peptide IIB (MIIB1 and MIIB2) and a minor band stained by anti-peptide IIA (MIIA2). Polyclonal anti-human platelet myosin antibodies did not react with MIIB isoforms. In cryosections from bovine, rat, and mouse brains, anti-peptide IIB stained most neuronal cells. In bovine cryosections, glial staining was also observed. In contrast, anti-peptide IIA and anti-platelet myosin antibodies primarily stained blood vessels. In bovine aorta, the anti-peptide antibodies recognized four bands, MIIB3, MIIB4, MIIA1, and MIIA2. Only MIIA2 was recognized by anti-human platelet myosin antibodies. In bovine aorta cryosections, anti-peptide IIB stained smooth muscle cells in tunica intima and tunica media but did not stain endothelial cells. Anti-peptide IIA stained smooth muscle cells in the tunica media, and endothelial cells of vaso vasorum but not of aorta. Only polyclonal anti-platelet myosin antibodies stained the endothelial cells of aorta tunica intima. These results indicate that multiple isoforms of cellular myosins exist in mammals, that these isoforms are expressed in a cell specific manner, and that the major myosin isoforms isolated from whole brain originate from neurons and, at least in bovine brain, from glia, but not from blood vessels.
authors.affiliation: Laboratory of Neurobiochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island 10314.
authors.forename: N
authors.initials: N
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Elzinga
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000201:enzymology*; D001921:Brain / Q000166:cytology; D001923:Brain Chemistry / Q000502:physiology*; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009218:Myosins / Q000032:analysis*; D051381:Rats; D012689:Sequence Homology, Nucleic Acid
chemical_list: D009218:Myosins