Subcellular Trafficking of the Nuclear Receptor COUP-TF in the Early Embryonic Cell Cycle
| Autor: | Constantin N. Flytzanis, Antonia Vlahou |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Embryo
Nonmammalian Mitosis Receptors Cytoplasmic and Nuclear Biology orphan nuclear receptor subcellular trafficking Chromosomes sea urchin biology.animal Animals Humans maternal transcription factor Sea urchin Transcription factor Molecular Biology Cell Nucleus Cell Cycle Embryo Biological Transport Cell Biology Cell cycle Subcellular localization chromosomal localization Molecular biology Nuclear receptor Cytoplasm embryonic development Fertilization Sea Urchins COUP-TF Subcellular Fractions Transcription Factors Developmental Biology |
| Zdroj: | Developmental Biology. 218(2):284-298 |
| ISSN: | 0012-1606 |
| DOI: | 10.1006/dbio.1999.9456 |
| Popis: | The nuclear receptor SpCOUP-TF is the highly conserved sea urchin homologue of the COUP family of transcription factors. Previous results from our laboratory demonstrated that SpCOUP-TF transcripts are localized in the egg and asymmetrically distributed in the early embryonic blastomeres (A. Vlahou et al., 1996, Development 122, 521–526). To examine the subcellular localization of SpCOUP-TF protein, polyclonal antibodies were separately raised against the divergent N-terminus as well as the conserved DNA-binding and ligand-binding domains. Immunohistochemical analyses suggest that SpCOUP-TF is a maternal protein residing in the cytoplasm of the unfertilized egg. After fertilization, and as soon as the two-cell-stage embryo, most of the receptor translocates from the cytoplasm to the cell nuclei. During the rapid embryonic cell division, SpCOUP-TF was found to shuttle from the interphase nuclear periphery to the condensed chromosomes in mitosis, in a cell-cycle-dependent manner. In an attempt to confirm these observations, the subcellular localization of myc-tagged human COUP-TF I introduced into the sea urchin embryo by RNA injection of fertilized eggs was examined. The pattern of human COUP-TF I subcellular localization, detected with a monoclonal myc antibody, recapitulated the essential features described for the endogenous SpCOUP-TF trafficking. Replacement of the N-terminus of the human receptor with the unique sea urchin N-terminus enhanced its localization to the nuclear rim during interphase. Deletion of the DNA-binding domain of human COUP-TF I resulted in loss of all aspects of nuclear periphery and chromosomal localization. Taken together these data suggest that SpCOUP-TF transcriptional activity is keyed on a cell-cycle-dependent mechanism that regulates chromosomal protein traffic. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect