title: AmpA, a modular protein containing disintegrin and ornatin domains, has multiple effects on cell adhesion and cell fate specification.
abstract: Proteins containing disintegrin domains play a variety of roles in regulating processes involving adhesion, migration and cell type specification during development of many metazoan organisms. Most disintegrin domain containing proteins belong to the ADAM (a disintegrin and a metalloprotease) family of proteins that also contain a metalloprotease domain. Here we describe a small secreted protein from Dictyostelium that contains multiple repeated domains sharing homology with both the disintegrin motif and with a second class of fibrinogen receptor antagonists, the ornatins. This protein, called AmpA for its role in modulating adhesion, differs from the ADAM family proteins in that it lacks a metalloprotease domain. Nonetheless, it appears to be involved in the same complex spectrum of developmental functions as the metazoan ADAM family proteins. Here we review the structure and evolution of this protein and its function in cell adhesion and cell type specification. We discuss possible mechanisms by which it might function and review the emerging evidence for a close coupling between cell adhesion and cell type specification.
authors.affiliation: Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA. blumberg@umbc.edu
authors.forename: Daphne D
authors.initials: DD
authors.lastname: Blumberg
authors.forename: Hoa N
authors.initials: HN
authors.lastname: Ho
authors.forename: Chere' L
authors.initials: CL
authors.lastname: Petty
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Varney
authors.forename: Srilatha
authors.initials: S
authors.lastname: Gandham
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D004023:Dictyostelium / Q000166:cytology* / Q000502:physiology*; D019483:Disintegrins / Q000737:chemistry / Q000378:metabolism*; D007447:Invertebrate Hormones / Q000378:metabolism*; D008322:Mammals; D008666:Metalloendopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009068:Movement / Q000502:physiology; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D019483:Disintegrins; D007447:Invertebrate Hormones; D015800:Protozoan Proteins; C072214:ornatin; C478220:AmpA protein, Dictyostelium protozoan; D008666:Metalloendopeptidases