RRC ID 6657
Author Mitra BN, Yoshino R, Morio T, Yokoyama M, Maeda M, Urushihara H, Tanaka Y.
Title Loss of a member of the aquaporin gene family, aqpA affects spore dormancy in Dictyostelium.
Journal Gene
Abstract We isolated and characterized a gene from Dictyostelium discoideum, which encodes a protein of 279 amino acids (30.6kDa) containing six transmembrane domains with two highly conserved motifs of asparagine-proline-alanine (NPA) found in the aquaporin family of water-channel proteins, although the second motif of the protein has been modified into NPV (asparagine-proline-valine). The deduced amino acid sequence of the gene, which we have named aqpA, is 39% identical to D. discoideum WacA, 26% identical to human Aqp5, 26% identical to Oryza sativa PIP2a, 25% identical to yeast Aqy1 and 24% identical to E.coli AqpZ. Southern analyses indicated that aqpA is present as a single copy in the genome. Northern blot analysis showed that the developmentally regulated 1kb mRNA transcript first appears at the tight mound stage (12h), and is abundant in fingers (16h) and late culminants (20h). In-situ hybridization of slugs revealed that aqpA mRNA accumulated in cells of the prespore region but not in those of the prestalk region. Disruption of aqpA by homologous recombination did not significantly affect growth or developmental morphogenesis. Although mutant spores were viable, when assayed soon after encapsulation, they became permeable to propidium iodide and lost viability after a week on the top of a fruiting body. Thus, AqpA is essential to maintain spore dormancy perhaps through the regulation of water flow.
Volume 251(2)
Pages 131-9
Published 2000-6-27
DOI 10.1016/s0378-1119(00)00201-8
PII S0378-1119(00)00201-8
PMID 10876090
MeSH Amino Acid Sequence Animals Aquaporins / genetics* Base Sequence Cell Division / genetics DNA / chemistry DNA / genetics DNA, Complementary / chemistry DNA, Complementary / genetics Dictyostelium / cytology Dictyostelium / genetics* Dictyostelium / physiology Gene Expression Regulation, Developmental Microscopy, Fluorescence Molecular Sequence Data Mutagenesis Protozoan Proteins* Sequence Alignment Sequence Analysis, DNA Sequence Homology, Amino Acid Spores / physiology
IF 2.984
Times Cited 19
Cellular slime molds G01921 S00237