title: Cloning of the murine non-muscle myosin heavy chain IIA gene ortholog of human MYH9 responsible for May-Hegglin, Sebastian, Fechtner, and Epstein syndromes.
abstract: Mutations in the non-muscle myosin heavy chain IIA gene (MYH9) are responsible for May-Hegglin anomaly, Sebastian, Fechtner and Epstein syndromes. These 'MYH9-related' diseases are inherited as an autosomal dominant trait and are characterized by a variable expressivity of clinical features, including macrothrombocytopenia, deafness, nephrites, cataract, and Döhle-like leukocyte inclusions. To gain information of the function of the non-muscle myosin heavy chain IIA protein (NMMHC-IIA), we have identified the murine orthologue Myh9 gene. The gene is localized in a region of chromosome 15 and encodes a predicted protein of 1960 amino acids. This protein shows a high homology to the human NMMHC-IIA with 98% identity. The Myh9 exon-intron junctions were deduced from a murine genomic clone that revealed a perfect conservation of the exon structure between the human and mouse gene. Myh9 is expressed in liver, kidney, lung, and spleen. A low level of transcripts was detected also in heart and brain while no expression was revealed in skeletal muscle and testis. In vertebrates, NMMHC-IIA shows a striking degree of homology to NMMHC-IIB, which is expressed at higher level in mouse brain and testis than in other tissues, confirming the hypothesis that the two non-muscle myosins have different functional roles within cells.
authors.affiliation: Servizio di Genetica Medica, IRCCS-Ospedale CSS, I-71013 San Giovanni Rotondo, Foggia, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: D'Apolito
authors.forename: Vito
authors.initials: V
authors.lastname: Guarnieri
authors.forename: Marianna
authors.initials: M
authors.lastname: Boncristiano
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Zelante
authors.forename: Anna
authors.initials: A
authors.lastname: Savoia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001791:Blood Platelet Disorders / Q000235:genetics* / Q000473:pathology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D003638:Deafness / Q000235:genetics / Q000473:pathology; D015870:Gene Expression; D006801:Humans; D008297:Male; D051379:Mice; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D018995:Myosin Heavy Chains / Q000235:genetics*; D009394:Nephritis, Hereditary / Q000235:genetics / Q000473:pathology; D024507:Nonmuscle Myosin Type IIA / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013577:Syndrome; D013921:Thrombocytopenia / Q000235:genetics* / Q000473:pathology
chemical_list: D018076:DNA, Complementary; C103814:MYH9 protein, human; D020409:Molecular Motor Proteins; D024507:Nonmuscle Myosin Type IIA; D018995:Myosin Heavy Chains