Characterization of a PDK1 Homologue from the Moss <i>Physcomitrella patens</i>

Dittrich, Anna C. Nelson; Devarenne, Timothy P.

doi:10.1104/pp.111.184572

Cited by 12 publications

(18 citation statements)

References 55 publications

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“…1C), PpPTENs exhibited different affinities for PPI isomers, including no lipid phosphatase activity for PpPTEND. Analogous observation was made for the moss Ser/Thr protein kinase PDK1, which was reported to lack a phospholipid-binding domain (Dittrich and Devarenne, 2012), suggesting that in nonvascular land plants, lipid regulation evolved differently.…”

Section: Ppptens Exert Their Role Through Changes In Ppi Levels and Rmentioning

confidence: 87%

Phosphatase and tensin homolog (PTEN) is a growth repressor of both rhizoid and gametophore development in the moss Physcomitrella patens.

et al. 2015

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Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid phosphatase implicated in cellular proliferation and survival. In animal cells, loss of PTEN leads to increased levels of phosphatidylinositol (3,4,5)-trisphosphate, stimulation of glucose and lipid metabolism, cellular growth, and morphological changes (related to adaptation and survival). Intriguingly, in plants, phosphatidylinositol (3,4,5)-trisphosphate has not been detected, and the enzymes that synthesize it were never reported. In this study we performed a genetic, biochemical, and functional characterization of the moss Physcomitrella patens PTEN gene family. P. patens has four PTENs, which are ubiquitously expressed during the entire moss life cycle. Using a knock-in approach, we show that all four genes are expressed in growing tissues, namely caulonemal and rhizoid cells. At the subcellular level, PpPTEN-green fluorescent protein fusions localized to the cytosol and the nucleus. Analysis of single and double knockouts revealed no significant phenotypes at different developmental stages, indicative of functional redundancy. However, compared with wild-type triple and quadruple pten knockouts, caulonemal cells grew faster, switched from the juvenile protonemal stage to adult gametophores earlier, and produced more rhizoids. Furthermore, analysis of lipid content and quantitative real-time polymerase chain reaction data performed in quadruple mutants revealed altered phosphoinositide levels [increase in phosphatidylinositol (3,5)-bisphosphate and decrease in phosphatidylinositol 3-phosphate] and up-regulation of marker genes from the synthesis phase of the cell cycle (e.g. P. patens proliferating cell nuclear antigen, ribonucleotide reductase, and minichromosome maintenance) and of the retinoblastoma-related protein gene P. patens retinoblastomarelated protein1. Together, these results suggest that PpPTEN is a suppressor of cell growth and morphogenic development in plants.

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Section: Ppptens Exert Their Role Through Changes In Ppi Levels and Rmentioning

confidence: 87%

Phosphatase and tensin homolog (PTEN) is a growth repressor of both rhizoid and gametophore development in the moss Physcomitrella patens.

et al. 2015

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“…Therefore, we were somewhat surprised to find that unlike previously reported plant PDK1s, the PDK1 homologue of the moss Physcomitrella patens lacks a PH domain. 27 This also appears to be true in putative PDK1s from several other species of Archaeplastida (consisting of land plants plus red, green, glaucophyte and charophyte algae). 27 To better understand the evolution of PDK1 structure and function, we have investigated putative PDK1 homologues from highly divergent eukaryotes, attempted to categorize them based on similarity within the catalytic domain.…”

mentioning

confidence: 85%

“…27 This also appears to be true in putative PDK1s from several other species of Archaeplastida (consisting of land plants plus red, green, glaucophyte and charophyte algae). 27 To better understand the evolution of PDK1 structure and function, we have investigated putative PDK1 homologues from highly divergent eukaryotes, attempted to categorize them based on similarity within the catalytic domain. Second, sequences were classified by the presence or absence of the six highly conserved PIF-binding pocket residues identified in the sequence alignment ( Fig.…”

mentioning

confidence: 85%

“…In agreement with a previous report in reference 26, our qualitative in vitro lipid-binding assays found that PDK1s from both A. thaliana and tomato (Solanum lycopersicum) strongly interact with phosphorylated phosphoinositides including PtdIns3P, PtdIns(4,5)P 2 and PA. 27 However, the P. patens PDK1 lacks a detectable lipid-binding domain and accordingly does not strongly bind either phospholipids or sphingolipids. 27 A search for PDK1s from divergent photosynthetic and non-photosynthetic organisms recovered 37 putative PDK1 proteins lacking any strongly identified lipid interaction domains ( Figs. 1 and 2).…”

Section: Analysis Of Pdk1 Sequences From Diverse Eukaryotesmentioning

confidence: 99%

“…In animals and fungi, PDK1 null alleles have thus far proven to be lethal. [23][24][25]48,49 In contrast, loss of PDK1 in Amoebozoa 45 and plants 27,38 produces viable, though compromised organisms. In both A. thaliana and P. patens, all apparent PDK1 non-photosynthetic species have a lipid-binding domain and others do not.…”

Section: Analysis Of Pdk1 Sequences From Diverse Eukaryotesmentioning

confidence: 99%

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Perspectives in PDK1 evolution

Dittrich

Devarenne

2012

Plant Signaling & Behavior

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Protein kinases belonging to the AGC group modulate many diverse cellular processes in all eukaryotes. One important way to regulate AGC kinases is through phosphorylation by the upstream kinase PDK1. PDK1 localization and activity usually depend on interactions with phospholipids, which are mediated by a conserved lipid-binding pleckstrin homology (PH) domain. We recently analyzed putative PDK1 sequences from 17 photosynthetic organisms, finding that PDK1s from vascular and nonvascular species seem to be distinguished by the presence or absence of a PH domain, respectively. The only other reported PDK1 lacking a PH domain is from yeast (Saccharomyces cerevisiae). These observations raise questions about how plant PDK1s and their lipid-binding capabilities have evolved in relation to other eukaryotes, and what this means for PDK1 function. Here we use 100 PDK1 sequences from diverse organisms to discuss possible evolutionary aspects of plant PDK1 structure and lipid binding.

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Role of AGC kinases in plant growth and stress responses

García¹,

Alyousif²,

Hirt³

2012

Cell. Mol. Life Sci.

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AGC kinases are important regulators of cell growth, metabolism, division, and survival in mammalian systems. Mutation or deregulation of members of this family of protein kinases contribute to the pathogenesis of many human diseases, including cancer and diabetes. Although AGC kinases are conserved in the plant kingdom, little is known about their molecular functions and targets. Some of the best-studied plant AGC kinases mediate auxin signaling and are thereby involved in the regulation of growth and morphogenesis. Furthermore, certain members are regulated by lipid-derived signals via the 3-phosphoinositide-dependent kinase 1 (PDK1) and the kinase target of rapamycin (TOR), similar to its animal counterparts. In this review, we discuss recent findings on plant AGC kinases that unravel important roles in the regulation of plant growth, immunity and cell death, and connections to stress-induced mitogen-activated protein kinase signaling cascades.

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Characterization of a PDK1 Homologue from the Moss Physcomitrella patens

Cited by 12 publications

References 55 publications

Phosphatase and tensin homolog (PTEN) is a growth repressor of both rhizoid and gametophore development in the moss Physcomitrella patens.

Phosphatase and tensin homolog (PTEN) is a growth repressor of both rhizoid and gametophore development in the moss Physcomitrella patens.

Perspectives in PDK1 evolution

Role of AGC kinases in plant growth and stress responses

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