title: The carboxy terminus of Prospero regulates its subcellular localization.
abstract: Subcellular localization of the transcription factor Prospero is dynamic. For example, the protein is cytoplasmic in neuroblasts, nuclear in sheath cells, and degraded in newly formed neurons. The carboxy terminus of Prospero, including the homeodomain and Prospero domain, plays roles in regulating these changes. The homeodomain has two distinct subdomains, which exclude proteins from the nucleus, while the intact homeo/Prospero domain masks this effect. One subdomain is an Exportin-dependent nuclear export signal requiring three conserved hydrophobic residues, which models onto helix 1. Another, including helices 2 and 3, requires proteasome activity to degrade nuclear protein. Finally, the Prospero domain is missing in pros(I13) embryos, thus unmasking nuclear exclusion, resulting in constitutively cytoplasmic protein. Multiple processes direct Prospero regulation of cell fate in embryonic nervous system development.
authors.affiliation: Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Bi
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Kajava
authors.forename: Tamara
authors.initials: T
authors.lastname: Jones
authors.forename: Zoya N
authors.initials: ZN
authors.lastname: Demidenko
authors.forename: Mark A
authors.initials: MA
authors.lastname: Mortin
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C073099:pros protein, Drosophila; D004247:DNA