RRC ID 29076
Author Bader S, Kortholt A, Snippe H, Van Haastert PJ.
Title DdPDE4, a novel cAMP-specific phosphodiesterase at the surface of dictyostelium cells.
Journal J Biol Chem
Abstract Dictyostelium discoideum cells possess multiple cyclic nucleotide phosphodiesterases that belong either to class I enzymes that are present in all eukaryotes or to the rare beta-lactamase class II. We describe here the identification and characterization of DdPDE4, the third class I enzyme of Dictyostelium. The deduced amino acid sequence predicts that DdPDE4 has a leader sequence, two transmembrane segments, and an extracellular catalytic domain that exhibits a high degree of homology with human cAMP-specific PDE8. Expression of the catalytic domain of DdPDE4 shows that the enzyme is a cAMP-specific phosphodiesterase with a K(m) of 10 microm; cGMP is hydrolyzed at least 100-fold more slowly. The full-length protein is shown to be membrane-bound with catalytic activity exposed to the extracellular medium. Northern blots and activity measurements reveal that expression of DdPDE4 is low during single cell stages and increases at 9 h of starvation, corresponding with mound stage. A function during multicellular development is confirmed by the phenotype of ddpde4(-) knock-out strains, showing normal aggregation but impaired development from the mound stage on. These results demonstrate that DdPDE4 is a unique membrane-bound phosphodiesterase with an extracellular catalytic domain regulating intercellular cAMP during multicellular development.
Volume 281(29)
Pages 20018-26
Published 2006-7-21
DOI 10.1074/jbc.M600040200
PII S0021-9258(19)76316-9
PMID 16644729
MeSH 3',5'-Cyclic-AMP Phosphodiesterases / chemistry 3',5'-Cyclic-AMP Phosphodiesterases / genetics* 3',5'-Cyclic-AMP Phosphodiesterases / metabolism* Amino Acid Sequence Animals Cell Membrane / enzymology* Conserved Sequence Cyclic AMP Cyclic Nucleotide Phosphodiesterases, Type 4 DNA Primers Dictyostelium / enzymology* Dictyostelium / genetics Gene Deletion Humans Molecular Sequence Data Phenotype Polymerase Chain Reaction Protozoan Proteins / metabolism Sequence Alignment Sequence Homology, Amino Acid
IF 4.238
Times Cited 16
Cellular slime molds S00336