Pigment epithelium-derived factor (PEDF) interacts with transportin SR2, and active nuclear import is facilitated by a novel nuclear localization motif

Autor: Michelle A. Morrin, William McCormack, Denise M. Fox, Sergio Anguissola, Wayne J. Higgins, D. Margaret Worrall
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Proteomics
Models
Molecular
Amino Acid Motifs
Nuclear Localization Signals
lcsh:Medicine
Protein Synthesis
Biochemistry
Protein Structure
Secondary
Mutant protein
Molecular Cell Biology
Macromolecular Structure Analysis
Signaling in Cellular Processes
lcsh:Science
Multidisciplinary
Physics
beta Karyopherins
Cellular Structures
medicine.anatomical_structure
Protein Classes
Karyopherins
Cellular Types
Research Article
Signal Transduction
Protein Binding
Signal peptide
Protein Structure
Molecular Sequence Data
Biophysics
Active Transport
Cell Nucleus
Biology
Protein Chemistry
PEDF
Two-Hybrid System Techniques
medicine
Humans
NLS
Amino Acid Sequence
Nerve Growth Factors
Protein Interactions
Eye Proteins
Serpins
Cell Nucleus
lcsh:R
Proteins
Computational Biology
Epithelial Cells
Molecular Development
Signaling
Peptide Fragments
Signaling Networks
Cell nucleus
HEK293 Cells
Mutagenesis
Site-Directed
lcsh:Q
Nuclear transport
Nuclear localization sequence
Developmental Biology
Zdroj: PLoS ONE, Vol 6, Iss 10, p e26234 (2011)
PLoS ONE
ISSN: 1932-6203
Popis: PEDF (Pigment epithelium-derived factor) is a non-inhibitory member of the serpin gene family (serpinF1) that displays neurotrophic and anti-angiogenic properties. PEDF contains a secretion signal sequence, but although originally regarded as a secreted extracellular protein, endogenous PEDF is found in the cytoplasm and nucleus of several mammalian cell types. In this study we employed a yeast two-hybrid interaction trap screen to identify transportin-SR2, a member of the importin-β family of nuclear transport karyopherins, as a putative PEDF binding partner. The interaction was supported in vitro by GST-pulldown and co-immunoprecipitation. Following transfection of HEK293 cells with GFP-tagged PEDF the protein was predominantly localised to the nucleus, suggesting that active import of PEDF occurs. A motif (YxxYRVRS) shared by PEDF and the unrelated transportin-SR2 substrate, RNA binding motif protein 4b, was identified and we investigated its potential as a nuclear localization signal (NLS) sequence. Site-directed mutagenesis of this helix A motif in PEDF resulted in a GFP-tagged mutant protein being excluded from the nucleus, and mutation of two arginine residues (R67, R69) was sufficient to abolish nuclear import and PEDF interaction with transportin-SR2. These results suggest a novel NLS and mechanism for serpinF1 nuclear import, which may be critical for anti-angiogenic and neurotrophic function.
Databáze: OpenAIRE
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