TY - JOUR
T1 - The cloning and characterization of a maternally expressed novel zinc finger nuclear phosphoprotein (xnf7) in Xenopus laevis
AU - Reddy, Bramham A.
AU - Kloc, Malgorzata
AU - Etkin, Laurence
N1 - Funding Information:
We thank Dr. Jiaxin Liu of the Department of Molecular Pathology, UTMDACC, for helping with the phosphoamino acid analysis. We also thank Peggy Billingsley and Teresa Parker for technical assistance. This work was supported by Grant DCB-900’7410 from the National Science Foundation to L.D.E. The accession number for xnf7 is M63705.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 1991/11
Y1 - 1991/11
N2 - We report the cloning of a cDNA (xnf7) coding for a maternally expressed Xenopus protein that becomes highly enriched in nuclei of the central nervous system during later development and in nuclei of adult brain. The protein also shows stage-specific nuclear/cytoplasmic partitioning and phosphorylation that may be related to its function. In addition, it binds to double-stranded DNA in vitro. The conceptual protein produced by the xnf7 clone contains several acidic domains, a novel zinc finger domain, three putative p34cdc2 protein kinase phosphorylation sites, and a bipartite basic nuclear localization signal. The xnf7 mRNA was detected as a maternal transcript that decreased in abundance during development through the gastrula stage. It was reexpressed at the neural stage in mesoderm and neural tissues, and its reexpression was not dependent upon the normal juxtaposition of the mesoderm and ectoderm that occurs during neural induction as demonstrated by high titer in exogastrulae. In situ hybridization showed enrichment of the mRNA in the neural tube and a small amount in the mesoderm at the late neurula stage. Xnf7 is normally phosphorylated during oocyte maturation. The bacterially expressed xnf7 protein was phosphorylated in vitro by purified maturation-promoting factor at a threonine in a small N-terminal domain containing one of the p34cdc2 protein kinase phosphorylation sites, but not by several other protein kinases. The structural domains present in the protein and its localization in nuclei suggest that the xnf7 gene product performs an important nuclear function during early development, perhaps as a transcription factor or a structural component of chromatin.
AB - We report the cloning of a cDNA (xnf7) coding for a maternally expressed Xenopus protein that becomes highly enriched in nuclei of the central nervous system during later development and in nuclei of adult brain. The protein also shows stage-specific nuclear/cytoplasmic partitioning and phosphorylation that may be related to its function. In addition, it binds to double-stranded DNA in vitro. The conceptual protein produced by the xnf7 clone contains several acidic domains, a novel zinc finger domain, three putative p34cdc2 protein kinase phosphorylation sites, and a bipartite basic nuclear localization signal. The xnf7 mRNA was detected as a maternal transcript that decreased in abundance during development through the gastrula stage. It was reexpressed at the neural stage in mesoderm and neural tissues, and its reexpression was not dependent upon the normal juxtaposition of the mesoderm and ectoderm that occurs during neural induction as demonstrated by high titer in exogastrulae. In situ hybridization showed enrichment of the mRNA in the neural tube and a small amount in the mesoderm at the late neurula stage. Xnf7 is normally phosphorylated during oocyte maturation. The bacterially expressed xnf7 protein was phosphorylated in vitro by purified maturation-promoting factor at a threonine in a small N-terminal domain containing one of the p34cdc2 protein kinase phosphorylation sites, but not by several other protein kinases. The structural domains present in the protein and its localization in nuclei suggest that the xnf7 gene product performs an important nuclear function during early development, perhaps as a transcription factor or a structural component of chromatin.
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U2 - 10.1016/0012-1606(91)90321-S
DO - 10.1016/0012-1606(91)90321-S
M3 - Article
C2 - 1936552
AN - SCOPUS:0025999551
VL - 148
SP - 107
EP - 116
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 1
ER -