title: Myosin XVA expression in the pituitary and in other neuroendocrine tissues and tumors.
abstract: The myosin superfamily of molecular motor proteins includes conventional myosins and several classes of unconventional myosins. Recent studies have characterized the human and mouse unconventional myosin XVA, which has a role in the formation and/or maintenance of the unique actin-rich structures of inner ear sensory hair cells. Myosin XVA is also highly expressed in human anterior pituitary cells. In this study we examined the distribution of myosin XVA protein and mRNA in normal and neoplastic human pituitaries and other neuroendocrine cells and tumors. Myosin XVA was expressed in all types of normal anterior pituitary cells and pituitary tumors and in other neuroendocrine cells and tumors including those of the adrenal medulla, parathyroid, and pancreatic islets. Most nonneuroendocrine tissues examined including liver cells were negative for myosin XVA protein and mRNA, although the distal and proximal tubules of normal kidneys showed moderate immunoreactivity for myosin XVA. Ultrastructural immunohistochemistry localized myosin XVA in association with secretory granules of human anterior pituitary cells and human pituitary tumors. These data suggest that in neuroendocrine cells myosin XVA may have a role in secretory granule movement and/or secretion.
authors.affiliation: Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA. lloyd.ricardo@mayo.edu
authors.forename: R V
authors.initials: RV
authors.lastname: Lloyd
authors.forename: S
authors.initials: S
authors.lastname: Vidal
authors.forename: L
authors.initials: L
authors.lastname: Jin
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: E T
authors.initials: ET
authors.lastname: Boger
authors.forename: R A
authors.initials: RA
authors.lastname: Fridell
authors.forename: T B
authors.initials: TB
authors.lastname: Friedman
mesh_terms: D004701:Endocrine Gland Neoplasms / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009218:Myosins / Q000378:metabolism*; D009423:Nervous System Neoplasms / Q000378:metabolism* / Q000648:ultrastructure; D009490:Neurosecretory Systems / Q000378:metabolism* / Q000648:ultrastructure; D010902:Pituitary Gland / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: C485245:MYO15A protein, human; C114013:Myo15 protein, mouse; D009218:Myosins