Subcellular Localization of Multiple PREP2 Isoforms Is Regulated by Actin, Tubulin, and Nuclear Export

Autor: Klaus Haller, Eugene Daniels, Mark Featherstone, Isabel Rambaldi
Rok vydání: 2004
Předmět:
Cytoplasm
Microtubules
Biochemistry
Epitopes
Mice
Tubulin
Myosin
Protein Isoforms
Cytoskeleton
Cells
Cultured
Antibiotics
Antineoplastic
Cell biology
medicine.anatomical_structure
COS Cells
Fatty Acids
Unsaturated
Electrophoresis
Polyacrylamide Gel
RNA Interference
Protein Binding
DNA
Complementary
Blotting
Western
Green Fluorescent Proteins
Molecular Sequence Data
Active Transport
Cell Nucleus
Biology
Transfection
Microtubule
medicine
Animals
Immunoprecipitation
Amino Acid Sequence
Nuclear export signal
Molecular Biology
Actin
Cell Nucleus
Homeodomain Proteins
Base Sequence
DNA
Cell Biology
Blotting
Northern
Subcellular localization
Molecular biology
Actins
Protein Structure
Tertiary
Alternative Splicing
Cell nucleus
Microscopy
Fluorescence
NIH 3T3 Cells
Nuclear localization sequence
Transcription Factors
Zdroj: Journal of Biological Chemistry. 279:49384-49394
ISSN: 0021-9258
DOI: 10.1074/jbc.m406046200
Popis: The PREP, MEIS, and PBX families are mammalian members of the TALE (three amino acid loop extension) class of homeodomain-containing transcription factors. These factors have been implicated in cooperative DNA binding with the HOX class of homeoproteins, but PREP and MEIS interact with PBX in apparently non-HOX-dependent cooperative DNA binding as well. PREP, MEIS, and PBX have all been reported to reside in the cytoplasm in one or more tissues of the developing vertebrate embryo. In the case of PBX, cytoplasmic localization is due to the modulation of nuclear localization signals, nuclear export sequences, and interaction with a cytoplasmic anchoring factor, non-muscle myosin heavy chain II B. Here we report that murine PREP2 exists in multiple isoforms distinguished by interaction with affinity-purified antibodies raised to N- and C-terminal epitopes and by nuclear versus cytoplasmic localization. Alternative splicing gives rise to some of these PREP2 isoforms, including a 25-kDa variant lacking the C-terminal half of the protein and homeodomain and having the potential to act as dominant-negative. We further show that cytoplasmic localization is due to the concerted action of nuclear export, as evidenced by sensitivity to leptomycin B, and cytoplasmic retention by the actin and microtubule cytoskeletons. Cytoplasmic PREP2 colocalizes with both the actin and microtubule cytoskeletons and coimmunoprecipitates with actin and tubulin. Importantly, disruption of either cytoskeletal system redirects cytoplasmic PREP2 to the nucleus. We suggest that transcriptional regulation by PREP2 is modulated through the subcellular distribution of multiple isoforms and by interaction with two distinct cytoskeletal systems.
Databáze: OpenAIRE
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