Phenotype of a Mechanosensitive Channel Mutant, mid - 1 , in a Filamentous Fungus, Neurospora crassa
| Autor: | Roger R. Lew, Zohaib Abbas, Marinela I. Anderca, Stephen J. Free |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Adenosine Triphosphatases
Fungal protein Neurospora crassa Saccharomyces cerevisiae Mutant Turgor pressure Wild type Articles General Medicine Biology biology.organism_classification Microbiology Yeast Circadian Rhythm Fungal Proteins Biochemistry Mutation Extracellular Calcium Channels Mechanoreceptors Molecular Biology |
| Zdroj: | Eukaryotic Cell. 7:647-655 |
| ISSN: | 1535-9786 1535-9778 |
| Popis: | In the yeast Saccharomyces cerevisiae , the MID1 ( m ating- i nduced d eath) gene encodes a stretch-activated channel which is required for successful mating; the mutant phenotype is rescued by elevated extracellular calcium. Homologs of the MID1 gene are found in fungi that are morphologically complex compared to yeast, both Basidiomycetes and Ascomycetes . We explored the phenotype of a mid - 1 knockout mutant in the filamentous ascomycete Neurospora crassa . The mutant exhibits lower growth vigor than the wild type (which is not rescued by replete calcium) and mates successfully. Thus, the role of the MID-1 protein differs from that of the homologous gene product in yeast. Hyphal cytology, growth on diverse carbon sources, turgor regulation, and circadian rhythms of the mid-1 mutant are all similar to those of the wild type. However, basal turgor is lower than wild type, as is the activity of the plasma membrane H + -ATPase (measured by cyanide [CN − ]-induced depolarization of the energy-dependent component of the membrane potential). In addition, the mutant is unable to grow at low extracellular Ca 2+ levels or when cytoplasmic Ca 2+ is elevated with the Ca 2+ ionophore A23187. We conclude that the MID-1 protein plays a role in regulation of ion transport via Ca 2+ homeostasis and signaling. In the absence of normal ion transport activity, the mutant exhibits poorer growth. |
| Databáze: | OpenAIRE |
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