The cAMP Receptor Subtype cAR2 Is Restricted to a Subset of Prestalk Cells duringDictyosteliumDevelopment and Displays Unexpected DIF-1 Responsiveness
| Autor: | Chris Haynes, Yimin Yu, Andrea L. Bauman, Cheryl Jones, Charles L. Saxe |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Molecular Sequence Data
Cell Fluorescent Antibody Technique lac operon Receptors Cyclic AMP Fusion gene Gene expression Hydrocarbons Chlorinated Extracellular medicine Animals Dictyostelium Amino Acid Sequence Caenorhabditis elegans Proteins Receptor Gene Molecular Biology biology fungi Proteins Helminth Proteins Cell Biology biology.organism_classification Cell biology Hexanones medicine.anatomical_structure Immunology Carrier Proteins Plasmids Developmental Biology |
| Zdroj: | Developmental Biology. 174(2):202-213 |
| ISSN: | 0012-1606 |
| DOI: | 10.1006/dbio.1996.0066 |
| Popis: | Dictyostelium discoidium cells express a family of cell surface cAMP receptors, and these G-protein-coupled receptors are each expressed with unique spatial and temporal patterns. One of these receptors, cAR2, is present during the postaggregative stages of development and our previous work suggests that it is preferentially expressed in prestalk cells. We report here the isolation of the promoter for carB, the gene which encodes cAR2. Using this fragment to generate a carB::lacZ gene fusion construct, we investigated carB expression in detail. Expression is first detected at the tight aggregate stage and subsequently in a pattern reminiscent of the prestalk-specific gene ecmA. There are subtle differences, however, with ecmA being expressed significantly in the anterior-like cells of the migrating pseudoplasmodium and in the basal disc and lower cup supporting the sorus during terminal development. carB is not expressed in any of these places. The presence of these different prestalk cell subtypes was confirmed by double indirect immunofluorescence using anti-cAR2 and antib-galactosidase antibodies. While virtually all cAR2-expressing cells also express ecmA::lacZ, a substantial fraction of ecmA::lacZ-positive cells do not express cAR2. We also found the regulation of carB gene expression to differ from that of ecmA. carB expression is induced in vitro by extracellular cAMP, but surprisingly, not by DIF-1, a soluble molecule thought to be essential for the initiation of prestalk differentiation. Thus, cAR2 appears to be a cAMP receptor present on a restricted subset of prestalk cells and whose expression does not respond typically to the prestalk inducer DIF-1. DIF-1 sensitivity may, therefore, not be characteristic of all early prestalk differentiation. q 1996 Academic Press, Inc. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect