Phosphatidylinositol (PI) is an essential structural component of eukaryotic membranes that also serves as the common precursor for polyphosphoinositide (PPIn) lipids. Despite the recognized importance of PPIn species for signal transduction and membrane homeostasis, there is still a limited understanding of the relationship between PI availability and the turnover of subcellular PPIn pools. To address these shortcomings, we established a molecular toolbox for investigations of PI distribution within intact cells by exploiting the properties of a bacterial enzyme, PI-specific PLC (PI-PLC). Using these tools, we find a minor presence of PI in membranes of the ER, as well as a general enrichment within the cytosolic leaflets of the Golgi complex, peroxisomes, and outer mitochondrial membrane, but only detect very low steady-state levels of PI within the plasma membrane (PM) and endosomes. Kinetic studies also demonstrate the requirement for sustained PI supply from the ER for the maintenance of monophosphorylated PPIn species within the PM, Golgi complex, and endosomal compartments.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biosenzitivní techniky MeSH
- buněčná membrána metabolismus MeSH
- Cercopithecus aethiops MeSH
- COS buňky MeSH
- fosfatidylinositolfosfáty metabolismus MeSH
- fosfatidylinositoly metabolismus MeSH
- fosfolipasy typu C genetika metabolismus MeSH
- HEK293 buňky MeSH
- intracelulární membrány metabolismus MeSH
- kinetika MeSH
- konfokální mikroskopie MeSH
- lidé MeSH
- luminescentní proteiny genetika metabolismus MeSH
- rekombinantní fúzní proteiny genetika metabolismus MeSH
- systémy druhého messengeru MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- srovnávací studie MeSH
Phosphatidylcholine-hydrolysing phospholipase C, also known as non-specific phospholipase C (NPC), is a new member of the plant phospholipase family that reacts to environmental stresses such as phosphate deficiency and aluminium toxicity, and has a role in root development and brassinolide signalling. Expression of NPC4, one of the six NPC genes in Arabidopsis, was highly induced by NaCl. Maximum expression was observed from 3 h to 6 h after the salt treatment and was dependent on salt concentration. Results of histochemical analysis of P(NPC4):GUS plants showed the localization of salt-induced expression in root tips. On the biochemical level, increased NPC enzyme activity, indicated by accumulation of diacylglycerol, was observed as early as after 30 min of salt treatment of Arabidopsis seedlings. Phenotype analysis of NPC4 knockout plants showed increased sensitivity to salinity as compared with wild-type plants. Under salt stress npc4 plants had shorter roots, lower fresh weight, and reduced seed germination. Expression levels of abscisic acid-related genes ABI1, ABI2, RAB18, PP2CA, and SOT12 were substantially reduced in salt-treated npc4 plants. These observations demonstrate a role for NPC4 in the response of Arabidopsis to salt stress.
- MeSH
- Arabidopsis účinky léků enzymologie genetika metabolismus MeSH
- chlorid sodný metabolismus farmakologie MeSH
- fosfolipasy typu C genetika metabolismus fyziologie MeSH
- geneticky modifikované rostliny MeSH
- kořeny rostlin účinky léků enzymologie genetika metabolismus MeSH
- kyselina abscisová genetika metabolismus MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- proteiny huseníčku genetika metabolismus fyziologie MeSH
- regulace genové exprese u rostlin MeSH
- signální transdukce MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
