title: The Nuclear Proteome of a Vertebrate.
abstract: The composition of the nucleoplasm determines the behavior of key processes such as transcription, yet there is still no reliable and quantitative resource of nuclear proteins. Furthermore, it is still unclear how the distinct nuclear and cytoplasmic compositions are maintained. To describe the nuclear proteome quantitatively, we isolated the large nuclei of frog oocytes via microdissection and measured the nucleocytoplasmic partitioning of ∼9,000 proteins by mass spectrometry. Most proteins localize entirely to either nucleus or cytoplasm; only ∼17% partition equally. A protein's native size in a complex, but not polypeptide molecular weight, is predictive of localization: partitioned proteins exhibit native sizes larger than ∼100 kDa, whereas natively smaller proteins are equidistributed. To evaluate the role of nuclear export in maintaining localization, we inhibited Exportin 1. This resulted in the expected re-localization of proteins toward the nucleus, but only 3% of the proteome was affected. Thus, complex assembly and passive retention, rather than continuous active transport, is the dominant mechanism for the maintenance of nuclear and cytoplasmic proteomes.
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Wühr
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Güttler
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Leonid
authors.initials: L
authors.lastname: Peshkin
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Graeme C
authors.initials: GC
authors.lastname: McAlister
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Sonnett
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ishihara
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Aaron C
authors.initials: AC
authors.lastname: Groen
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Presler
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Erickson
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Mitchison
authors.affiliation: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: marc@hms.harvard.edu.
authors.forename: Marc W
authors.initials: MW
authors.lastname: Kirschner
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: steven_gygi@hms.harvard.edu.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gygi
mesh_terms: D029845:Amphibian Proteins / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D020543:Proteome / Q000235:genetics* / Q000378:metabolism; D014981:Xenopus / Q000235:genetics* / Q000378:metabolism
chemical_list: D029845:Amphibian Proteins; D009687:Nuclear Proteins; D020543:Proteome