Molecular basis of cellular localization of poly C binding protein 1 in neuronal cells.
Poly C binding protein 1 (PCBP) is involved in the transcriptional regulation of neuronal mu-opioid receptor gene. In this study, we examined the molecular basis of PCBP cellular/nuclear localization in neuronal cells using EGFP fusion protein. PCBP, containing three KH domains and a variable domain, 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, and PCBP variable domain contributed to this restricted nucleolar expression. Furthermore, the punctate nuclear pattern of PCBP was correlated to its single-stranded (ss) DNA binding ability, with both requiring cooperativity of at least three sequential domains. Collectively, certain PCBP domains thus govern its nuclear distribution and transcriptional regulatory activity in the nucleus of neurons, whereas the low nucleolar expression implicates the disengagement of PCBP in the ribosomal RNA synthesis.
Berry
Andrea M
AM
Department of Biology, Seton Hall University, 208 McNulty Hall, 400 South Orange Avenue, South Orange, NJ 07079, USA.
Flock
Kelly E
KE
Loh
Horace H
HH
Ko
Jane L
JL
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000378:metabolism
D002352:Carrier Proteins; C030929:Crp protein, rat; D011994:Recombinant Proteins