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A mutation that alters properties of the calcium channel in Paramecium tetraurelia.
| Content Provider | Scilit |
|---|---|
| Author | Hinrichsen, R. D. Saimi, Y. |
| Copyright Year | 1984 |
| Description | Journal: The Journal of physiology The membrane properties of a new mutant of Paramecium tetraurelia, dancer, were compared under voltage clamp with those of the wild type. The Ca2+ current was isolated and examined using CsCl-filled electrodes and tetraethylammonium in the bath solution to block K+ channels. The amplitude of the Ca2+ transient was not altered by the mutation. However, the Ca2+ current in the mutant inactivated more slowly and less extensively: hence a larger sustained Ca2+ current remained in the mutant. A change in the time course of the deactivation of the Ba2+ current was observed in the mutant. This mutational change is not likely to be the consequence of the Ca2+-channel inactivation because it is seen in the Ba2+ solution where there is little inactivation of the current. Other measured properties of the Ca2+ channel, the voltage-dependent K+ current, and the resting properties of the membrane were normal in the mutant. The Ca2+-activated K+ current and the Ca2+-activated Na+ current were larger in the mutant than in the wild type, consistent with a greater elevation of free intracellular Ca2+ during depolarization in the mutant. It is likely that the mutation causes an alteration in the Ca2+-channel structure or in its immediate environment and thereby affects the inactivation and deactivation processes of the Ca2+ channel. As would be expected from the greater Ca2+ current, the mutant tends to generate all-or-none Ca action potentials as opposed to the graded action potentials in the wild type. |
| Related Links | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1193124/pdf |
| Ending Page | 410 |
| Page Count | 14 |
| Starting Page | 397 |
| ISSN | 00223751 |
| e-ISSN | 14697793 |
| DOI | 10.1113/jphysiol.1984.sp015252 |
| Journal | The Journal of physiology |
| Issue Number | 1 |
| Volume Number | 351 |
| Language | English |
| Publisher | Wiley-Blackwell |
| Publisher Date | 1984-06-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: The Journal of physiology Biochemistry and Molecular Biology Calcium Channel Paramecium Tetraurelia Alters Properties Mutation That Alters Channel in Paramecium |
| Content Type | Text |
| Resource Type | Article |
| Subject | Physiology Sports Science |
