A tumor suppressor homolog, AtPTEN1, is essential for pollen development in Arabidopsis.
Although it is well known that Tyr phosphatases play a critical role in signal transduction in animal cells, little is understood of the functional significance of Tyr phosphatases in higher plants. Here, we describe the functional analysis of an Arabidopsis gene (AtPTEN1) that encodes a Tyr phosphatase closely related to PTEN, a tumor suppressor in animals. The recombinant AtPTEN1 protein, like its homologs in animals, is an active phosphatase that dephosphorylates phosphotyrosine and phosphatidylinositol substrates. RNA gel blot analysis and examination of promoter-reporter constructs in transgenic Arabidopsis plants revealed that the AtPTEN1 gene is expressed exclusively in pollen grains during the late stage of development. Suppression of AtPTEN1 gene expression by RNA interference caused pollen cell death after mitosis. We conclude that AtPTEN1 is a pollen-specific phosphatase and is essential for pollen development.
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009154:Mutation; D051059:PTEN Phosphohydrolase; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D018129:Phosphatidylinositol Phosphates; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; C060974:phosphatidylinositol 3,4,5-triphosphate; D019000:Phosphotyrosine; D017027:Protein Tyrosine Phosphatases; D051059:PTEN Phosphohydrolase; C470418:PTEN1 protein, Arabidopsis