Linked Life Data

21335528

Source:http://linkedlifedata.com/resource/pubmed/id/21335528

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-5-3
pubmed:abstractText
We have examined the distribution of calcium in Neurospora crassa and investigated the role of four predicted calcium transport proteins. The results of cell fractionation experiments showed 4% of cellular calcium in mitochondria, approximately 11% in a dense vacuolar fraction, 40% in an insoluble form that copurifies with microsomes, and 40% in a high-speed supernatant, presumably from large vacuoles that had broken. Strains lacking NCA-1, a SERCA-type Ca(2+)-ATPase, or NCA-3, a PMC-type Ca(2+)-ATPase, had no obvious defects in growth or distribution of calcium. A strain lacking NCA-2, which is also a PMC-type Ca(2+)-ATPase, grew slowly in normal medium and was unable to grow in high concentrations of calcium tolerated by the wild type. Furthermore, when grown in normal concentrations of calcium (0.68 mM), this strain accumulated 4- to 10-fold more calcium than other strains, elevated in all cell fractions. The data suggest that NCA-2 functions in the plasma membrane to pump calcium out of the cell. In this way, it resembles the PMC-type enzymes of animal cells, not the Pmc1p enzyme in Saccharomyces cerevisiae that resides in the vacuole. Strains lacking the cax gene, which encodes a Ca(2+)/H(+) exchange protein in vacuolar membranes, accumulate very little calcium in the dense vacuolar fraction but have normal levels of calcium in other fractions. The cax knockout strain has no other observable phenotypes. These data suggest that "the vacuole" is heterogeneous and that the dense vacuolar fraction contains an organelle that is dependent upon the CAX transporter for accumulation of calcium, while other components of the vacuolar system have multiple calcium transporters.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1535-9786
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
654-61
pubmed:dateRevised
2011-11-1
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Role of four calcium transport proteins, encoded by nca-1, nca-2, nca-3, and cax, in maintaining intracellular calcium levels in Neurospora crassa.
pubmed:affiliation
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA. bbowman@ucsc.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural