Calphotin: a Drosophila photoreceptor cell calcium-binding protein.
AUTOR(ES)
Martin, J H
RESUMO
Monoclonal antibody 23E9 identifies a calcium-binding protein, calphotin, in photoreceptor cells of the Drosophila melanogaster compound eyes and ocelli. The antigen is restricted to a defined cytoplasmic region; it is not present in the rhabdomeres, nuclei, mitochondria, or rough endoplasmic reticulum. A corresponding cDNA recognizes a 3-kb mRNA with retinal specificity similar to the antigen and maps to band 86E/F-87A/B on chromosome 3. An open reading frame of 2595 bp encodes an estimated 85-kDa protein of unusual amino acid composition, with > 50% proline, alanine, and valine and very few basic residues. The C-terminal segment contains a leucine zipper motif uninterrupted by prolines. We found no significant similarities with the GenBank or National Biomedical Resource Foundation data bases. The location of the protein within a distinct cytoplasmic region suggests that it might function as a calcium-sequestering "sponge" to regulate the amount of free cytoplasmic calcium.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=45908Documentos Relacionados
- Mutations in Calphotin, the Gene Encoding a Drosophila Photoreceptor Cell-Specific Calcium-Binding Protein, Reveal Roles in Cellular Morphogenesis and Survival
- Profilaggrin is a major epidermal calcium-binding protein.
- A Drosophila photoreceptor cell-specific protein, calphotin, binds calcium and contains a leucine zipper.
- Isolation, partial amino acid sequence, and immunohistochemical localization of a brain-specific calcium-binding protein.
- Calcium-binding proteins in human carcinoma cell lines.