Proteomic Analysis of Importin .ALPHA.-interacting Proteins in Adult Mouse Brain

• Fukumoto Masahiro

  Department of Frontier Biosciences, Osaka University Graduate School of Frontier Biosciences

• Sekimoto Toshihiro

  Department of Biochemistry, Osaka University Graduate School of Medicine

• Yoneda Yoshihiro

  Department of Frontier Biosciences, Osaka University Graduate School of Frontier Biosciences Department of Biochemistry, Osaka University Graduate School of Medicine CREST, Japan Science and Technology Agency, Osaka University

Bibliographic Information

Other Title

• Proteomic analysis of importin α-interacting proteins in adult mouse brain

Abstract

Many transport factors, such as importins and exportins, have been identified, and the molecular mechanisms underlying nucleocytoplasmic transport have been characterized. The specific molecules that are carried by each transport factor and the temporal profiles that characterize the movements of various proteins into or out of the nucleus, however, have yet to be elucidated. Here, we used a proteomic approach to identify molecules that are transported into the nuclei of adult mouse brain cells via importin α5. We identified 48 proteins in total, among which we chose seven to characterize more extensively: acidic (leucine-rich) nuclear phosphoprotein 32 family member A (Anp32a), far upstream element binding protein 1 (FUBP1), thyroid hormone receptor β1 (TRβ1), transaldolase 1, CDC42 effector protein 4 (CDC42-ep4), Coronin 1B, and brain-specific creatine kinase (CK-B). Analyses using green fluorescent protein (GFP)-fused proteins showed that Anp32a, FUBP1, and TRβ1 were localized in the nucleus, whereas transaldolase 1, CDC42-ep4, CK-B, and Coronin 1B were distributed in both the cytoplasm and nucleus. Using a digitonin-permeabilized in vitro transport assay, we demonstrated that, with the exception of CK-B, these proteins were transported into the nucleus by importin α5 together with importin β and Ran. Further, we found that leptomycin B (LMB) treatment increased nuclear CK-B-GFP signals, suggesting that CK-B enters the nucleus and is then exported in a CRM1-dependent manner. Thus, we identified a comprehensive set of candidate proteins that are transported into the nucleus in a manner dependent on importin α5, which enhances our understanding of nucleocytoplasmic signaling in neural cells.<br>

Journal

• Cell Structure and Function

  Cell Structure and Function 36 (1), 57-67, 2011

  Japan Society for Cell Biology

Keywords

• Nuclear protein transport
• importin α
• nuclear localization signal (NLS)
• neural cells

Details

• CRID: 1390001204696928512
• NII Article ID: 130004137564
• DOI: 10.1247/csf.10026
• ISSN: 13473700
• ISSN: 03867196
• Web Site: http://www.jstage.jst.go.jp/article/csf/36/1/36_10026/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed