RRC ID 29102
Author Araki Y, Shimizu HD, Saeki K, Okamoto M, Yamada L, Ishida K, Sawada H, Urushihara H.
Title A surface glycoprotein indispensable for gamete fusion in the social amoeba Dictyostelium discoideum.
Journal Eukaryot Cell
Abstract Sexual reproduction is essential for the maintenance of species in a wide variety of multicellular organisms, and even unicellular organisms that normally proliferate asexually possess a sexual cycle because of its contribution to increased genetic diversity. Information concerning the molecules involved in fertilization is accumulating for many species of the metazoan, plant, and fungal lineages, and the evolutionary consideration of sexual reproduction systems is now an interesting issue. Macrocyst formation in the social amoeba Dictyostelium discoideum is a sexual process in which cells become sexually mature under dark and submerged conditions and fuse with complementary mating-type cells. In the present study, we isolated D. discoideum insertional mutants defective in sexual cell fusion and identified the relevant gene, macA, which encodes a highly glycosylated, 2,041-amino-acid membrane protein (MacA). Although its overall similarity is restricted to proteins of unknown function within dictyostelids, it contains LamGL and discoidin domains, which are implicated in cell adhesion. The growth and development of macA-null mutants were indistinguishable from those of the parental strain. The overexpression of macA using the V18 promoter in a macA-null mutant completely restored its sexual defects. Although the macA gene encoded exactly the same protein in a complementary mating-type strain, it was expressed at a much lower level. These results suggest that MacA is indispensable for gamete interactions in D. discoideum, probably via cell adhesion. There is a possibility that it is controlled in a mating-type-dependent manner.
Volume 11(5)
Pages 638-44
Published 2012-5-1
DOI 10.1128/EC.00028-12
PII EC.00028-12
PMID 22389384
PMC PMC3346428
MeSH Amino Acid Sequence Cell Adhesion Cell Membrane / chemistry Conserved Sequence Dictyostelium / genetics Dictyostelium / growth & development* Dictyostelium / metabolism Discoidins Gene Expression Regulation, Developmental Genes, Protozoan Glycosylation Lectins / chemistry Membrane Glycoproteins / chemistry* Mutagenesis, Insertional / methods Promoter Regions, Genetic Protein Structure, Tertiary Protozoan Proteins / chemistry* Reproduction
IF 2.992
Times Cited 9
Cellular slime molds S00247 S90067 S90068 S90069 S90070 S90071 S90072 S90073 S90074 S90075 S90368