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Cytoplasmic retention of Xenopus nuclear factor 7 before the mid blastula transition uses a unique anchoring mechanism involving a retention domain and several phosphorylation sites.
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Xenopus nuclear factor 7 (xnf7) is a maternally expressed protein that belongs to the B-box zinc finger gene family consisting of transcription factors, protooncogenes, and ribonucleoproteins. Its function is regulated by retention in the cytoplasm from oocyte maturation until the mid blastula transition (MBT) when it reenters the nucleus. We defined a 22-amino acid cytoplasmic retention domain (CRD) in xnf7 that functioned cooperatively with two phosphorylation sites within the xnf7 molecule to retain the protein in the cytoplasm until the MBT. Deletion of this region or mutations in the phosphorylation sites resulted in the early entry of xnf7 into the nucleus. A mutation changing one of the phosphorylation sites to a glutamic acid resulted in the prolonged retention of the xnf7 protein in the cytoplasm until stages 9-10, well past the MBT. Additionally, a mutant form of xnf7 possessing a second nuclear localization signal at the COOH terminus was retained in the cytoplasm. This suggests that retention of xnf7 was not due to the masking of its NLS as is the case with NFkB and dorsal but was due to a novel anchoring mechanism in which the CRD interacts with an anchor protein. The CRD sequence is also found in another B-box zinc finger protein that is also retained in the cytoplasm until the MBT in the newt. Therefore, we believe that this may be an important mechanism whereby the function of a number of nuclear proteins is regulated during development.
Beg,
I kappa B interacts with the nuclear localization sequences of the subunits of NF-kappa B: a mechanism for cytoplasmic retention.
1992, Pubmed
Beg,
I kappa B interacts with the nuclear localization sequences of the subunits of NF-kappa B: a mechanism for cytoplasmic retention.
1992,
Pubmed Bellini,
A putative zinc-binding protein on lampbrush chromosome loops.
1993,
Pubmed Blank,
Cytoplasmic retention, DNA binding and processing of the NF-kappa B p50 precursor are controlled by a small region in its C-terminus.
1991,
Pubmed Cornish,
Xlcaax-1 is localized to the basolateral membrane of kidney tubule and other polarized epithelia during Xenopus development.
1992,
Pubmed
,
Xenbase Dreyer,
Differential accumulation of oocyte nuclear proteins by embryonic nuclei of Xenopus.
1987,
Pubmed
,
Xenbase Etkin,
Replication, integration and expression of exogenous DNA injected into fertilized eggs of Xenopus laevis.
1984,
Pubmed
,
Xenbase Etkin,
Distribution, expression and germ line transmission of exogenous DNA sequences following microinjection into Xenopus laevis eggs.
1987,
Pubmed
,
Xenbase Forbes,
Structure and function of the nuclear pore complex.
1992,
Pubmed
,
Xenbase Freemont,
The RING finger. A novel protein sequence motif related to the zinc finger.
1993,
Pubmed Gannon,
Protein synthesis required to anchor a mutant p53 protein which is temperature-sensitive for nuclear transport.
1991,
Pubmed Ghosh,
Activation in vitro of NF-kappa B by phosphorylation of its inhibitor I kappa B.
1990,
Pubmed Govind,
Dorsoventral pattern formation in Drosophila: signal transduction and nuclear targeting.
1991,
Pubmed Henkel,
Intramolecular masking of the nuclear location signal and dimerization domain in the precursor for the p50 NF-kappa B subunit.
1992,
Pubmed Hennekes,
Phosphorylation on protein kinase C sites inhibits nuclear import of lamin B2.
1993,
Pubmed Horton,
Gene splicing by overlap extension: tailor-made genes using the polymerase chain reaction.
1990,
Pubmed Hunt,
Cytoplasmic anchoring proteins and the control of nuclear localization.
1989,
Pubmed Jans,
p34cdc2-mediated phosphorylation at T124 inhibits nuclear import of SV-40 T antigen proteins.
1991,
Pubmed Kerr,
The rel-associated pp40 protein prevents DNA binding of Rel and NF-kappa B: relationship with I kappa B beta and regulation by phosphorylation.
1991,
Pubmed Kieran,
The DNA binding subunit of NF-kappa B is identical to factor KBF1 and homologous to the rel oncogene product.
1990,
Pubmed Lenardo,
NF-kappa B: a pleiotropic mediator of inducible and tissue-specific gene control.
1989,
Pubmed Li,
Xenopus nuclear factor 7 (xnf7) possesses an NLS that functions efficiently in both oocytes and embryos.
1993,
Pubmed
,
Xenbase Miller,
The nuclear-cytoplasmic distribution of the Xenopus nuclear factor, xnf7, coincides with its state of phosphorylation during early development.
1991,
Pubmed
,
Xenbase Miller,
xlgv7: a maternal gene product localized in nuclei of the central nervous system in Xenopus laevis.
1989,
Pubmed
,
Xenbase Moll,
The role of phosphorylation and the CDC28 protein kinase in cell cycle-regulated nuclear import of the S. cerevisiae transcription factor SWI5.
1991,
Pubmed Moll,
Two distinct mechanisms alter p53 in breast cancer: mutation and nuclear exclusion.
1992,
Pubmed Newport,
A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.
1982,
Pubmed
,
Xenbase Nigg,
Nuclear import-export: in search of signals and mechanisms.
1991,
Pubmed Picard,
Two signals mediate hormone-dependent nuclear localization of the glucocorticoid receptor.
1987,
Pubmed Pratt,
Control of steroid receptor function and cytoplasmic-nuclear transport by heat shock proteins.
1992,
Pubmed Reddy,
A unique bipartite cysteine-histidine motif defines a subfamily of potential zinc-finger proteins.
1991,
Pubmed
,
Xenbase Reddy,
The cloning and characterization of a maternally expressed novel zinc finger nuclear phosphoprotein (xnf7) in Xenopus laevis.
1991,
Pubmed
,
Xenbase Reddy,
A novel zinc finger coiled-coil domain in a family of nuclear proteins.
1992,
Pubmed Roth,
A gradient of nuclear localization of the dorsal protein determines dorsoventral pattern in the Drosophila embryo.
1989,
Pubmed Rushlow,
The graded distribution of the dorsal morphogen is initiated by selective nuclear transport in Drosophila.
1989,
Pubmed Schmitz,
Proteins controlling the nuclear uptake of NF-kappa B, Rel and dorsal.
1991,
Pubmed Silver,
How proteins enter the nucleus.
1991,
Pubmed Steward,
Relocalization of the dorsal protein from the cytoplasm to the nucleus correlates with its function.
1989,
Pubmed Whiteside,
Signal transduction and nuclear targeting: regulation of transcription factor activity by subcellular localisation.
1993,
Pubmed
