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Structural basis of poly C binding protein 1 and its cellular distribution
Author(s) -
Flock Kelly E.,
Berry Andrea M,
Loh Horace H.,
Ko Jane L
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a287-b
Subject(s) - cytoplasm , microbiology and biotechnology , nuclear protein , nuclear localization sequence , fusion protein , cell nucleus , nuclear pore , biology , nuclear export signal , gene , chemistry , transcription factor , genetics , recombinant dna
Poly C binding protein 1 (PCBP) participates in the transcriptional regulation of neuronal mu‐opioid receptor gene. In this study, we investigated the structural basis of PCBP related to its subcelluar localization in neuronal cells using EGFP fusion protein. PCBP distributed in cytoplasm and nucleus with a preferential nuclear expression. Domain‐deletional analyses suggested the requirement of variable and KH3 domains for strong PCBP nuclear expression. Within the nucleus, a low nucleolar PCBP expression was observed, implicating the disengagement of PCBP in the ribosomal RNA synthesis, and the variable domain contributed to this restricted nucleolar expression. The punctate nuclear pattern of PCBP was correlated to its single‐stranded DNA binding ability, with both requiring cooperativity of at least three sequential domains. Furthermore, preliminary results showed that cells treated with leptomycin B (LMB) to block the nuclear export displayed an enhancement of PCBP nuclear distribution as compared to that of the non‐treated cells. Summarily, data suggested that certain PCBP domains govern its subcellular distribution and transcriptional regulatory activity in the nucleus of neurons, and the involvement of CRM1 in the nuclear export of PCBP in neuronal cells.