FYVE-DSP2, a FYVE domain-containing dual specificity protein phosphatase that dephosphorylates phosphotidylinositol 3-phosphate.
We have recently isolated FYVE-DSP1, a FYVE domain-containing dual specificity protein phosphatase (R. Zhao, Y. Qi, and Z. J. Zhao, Biochem. Biophys. Res. Commun. 270, 222--229 (2000)). Here, we report a novel isozyme that we designated FYVE-DSP2. FYVE-2 contains a single FYVE domain at the C-terminus, and it shares approximately 47% overall sequence identity with FYBE-DSP1. Genomic sequence analyses revealed that the FYVE-DSP1 and FYVE-DSP2 genes share similar intron/exon organization. They are localizedon human chromosome 22q12 and chromosome 17, respectively. Like FYVE-DSP1, recombinant FYVE-DSP2 dephosphorylated low-molecular-weight phosphatase substrate para-nitrophenylphosphate, and its activity was inhibited by sodium vanadate. More importantly, our study also revealed that both FYVE-DSP1 and FYVE-DSP2 efficiently and specifically dephosphorylated phosphotidylinositol 3-phosphate. Subcellular fractionation demonstrated partition of FYVE-DSP1 and FYVE-DSP2 in membrane fractions, and immunofluorescent cell staining showed perinuclear localization of the enzymes. FYVE-DSP2 is expressed in many human tissues with an alternatively spliced isoform expressed in the kidney. Together with two homologous hypothetical proteins found in Caenorhabditis elegans and Drosophila, FYVE-DSP1 and FYVE-DSP2 form a subfamilyof phosphatases that may have an importantrole in cellular processes.
Zhao
R
R
Division of Hematology/Oncology, Vanderbilt-Ingram Cancer Center, Nashville, Tennessee, 37232-6305
Qi
Y
Y
Chen
J
J
Zhao
Z J
ZJ
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D015153:Blotting, Western; D002458:Cell Fractionation; D002460:Cell Line; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D054558:Protein Tyrosine Phosphatases, Non-Receptor; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D016335:Zinc Fingers / Q000235:genetics
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D018129:Phosphatidylinositol Phosphates; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C055525:phosphatidylinositol 3-phosphate; D010749:Phosphoprotein Phosphatases; D010744:Phosphoric Monoester Hydrolases; C444436:MTMR3 protein, human; C427064:MTMR4 protein, human; D017027:Protein Tyrosine Phosphatases; D054558:Protein Tyrosine Phosphatases, Non-Receptor