A diverse family of inositol 5-phosphatases playing a role in growth and development in Dictyostelium discoideum.
Inositol phosphate-containing molecules play an important role in a broad range of cellular processes. Inositol 5-phosphatases participate in the regulation of these signaling molecules. We have identified four inositol 5-phosphatases in Dictyostelium discoideum, Dd5P1-4, showing a high diversity in domain composition. Dd5P1 possesses only a inositol 5-phosphatase catalytic domain. An unique domain composition is present in Dd5P2 containing a RCC1-like domain. RCC1 has a seven-bladed propeller structure and interacts with G-proteins. Dd5P3 and Dd5P4 have a domain composition similar to human Synaptojanin with a SacI domain and OCRL with a RhoGAP domain, respectively. We have expressed the catalytic domains and show that these inositol 5-phosphatases have different substrate preferences. Single and double gene inactivation suggest a functional redundancy for Dd5P1, Dd5P2, and Dd5P3. Inactivation of the gene coding for Dd5P4 leads to defects in growth and development. These defects are restored by the expression of the complete protein but not by the 5-phosphatase catalytic domain.
Loovers
Harriet M
HM
Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Veenstra
Kees
K
Snippe
Helena
H
Pesesse
Xavier
X
Erneux
Christophe
C
van Haastert
Peter J M
PJ
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D004023:Dictyostelium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D014644:Genetic Variation; D006801:Humans; D000072181:Inositol Polyphosphate 5-Phosphatases; D007700:Kinetics; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D000099182:Phosphoinositide 5-Phosphatases
D000072181:Inositol Polyphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases; D000099182:Phosphoinositide 5-Phosphatases; C096024:phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase