論文 - 詳細
| RRC ID | 6713 |
|---|---|
| 著者 | Damer CK, Bayeva M, Hahn ES, Rivera J, Socec CI. |
| タイトル | Copine A, a calcium-dependent membrane-binding protein, transiently localizes to the plasma membrane and intracellular vacuoles in Dictyostelium. |
| ジャーナル | BMC Cell Biol |
| Abstract |
BACKGROUND:Copines are soluble, calcium-dependent membrane binding proteins found in a variety of organisms. Copines are characterized as having two C2 domains at the N-terminal region followed by an "A domain" at the C-terminal region. The "A domain" is similar in sequence to the von Willebrand A (VWA) domain found in integrins. The presence of C2 domains suggests that copines may be involved in cell signaling and/or membrane trafficking pathways. RESULTS:We have identified six copines genes in the Dictyostelium discoideum genome, cpnA-cpnF, and have focused our studies on cpnA. CpnA is expressed throughout development and was shown to be capable of binding to membranes in a calcium-dependent manner in vitro. A GFP-tagged CpnA was also capable of binding to membranes in a calcium-dependent manner in vitro. In live wildtype Dictyostelium cells expressing GFP-CpnA, GFP-CpnA was typically found in the cytoplasm without any specific localization to membranes. However, in a small subset of starved cells, GFP-CpnA was observed to bind transiently (typically approximately 1-10 s) to the plasma membrane and intracellular vacuoles. In some cells, the transient membrane localization of GFP-CpnA was observed to occur multiple times in an oscillatory manner over several minutes. In plasma membrane disrupted cells, GFP-CpnA was observed to associate with the plasma membrane and intracellular vacuoles in a calcium-dependent manner. In fixed cells, GFP-CpnA labeled the plasma membrane and intracellular vacuoles, including contractile vacuoles, organelles of the endolysosomal pathway, and phagosomes. CONCLUSION:Our results show that Dictyostelium has multiple copine homologs and provides an excellent system in which to study copine function. The localization of a GFP-tagged CpnA to the plasma membrane, contractile vacuoles, organelles of the endolysosomal pathway, and phagosomes suggests that CpnA may have a role in the function of these organelles or the trafficking to and from them. In addition, we hypothesize that the observed transient oscillatory membrane localization of GFP-CpnA in a small subset of starved cells is caused by fast calcium waves and speculate that CpnA may have a role in development, particularly in the differentiation of stalk cells. |
| 巻・号 | 6 |
| ページ | 46 |
| 公開日 | 2005-12-12 |
| DOI | 10.1186/1471-2121-6-46 |
| PII | 1471-2121-6-46 |
| PMID | 16343335 |
| PMC | PMC1327671 |
| MeSH | Animals Calcium / metabolism Carrier Proteins / genetics Carrier Proteins / metabolism* Cell Membrane / metabolism* Dictyostelium / cytology* Dictyostelium / metabolism* Endosomes / metabolism Genes, Reporter Lysosomes / metabolism Phagosomes / metabolism Protein Binding Protein Transport RNA, Messenger / genetics RNA, Messenger / metabolism Vacuoles / metabolism* |
| IF | 3.066 |
| 引用数 | 28 |
| WOS 分野 | CELL BIOLOGY |
| リソース情報 | |
| 細胞性粘菌 | G01124 |