Dataset Information

Expression of phosphatidylinositol (4,5) bisphosphate-specific pleckstrin homology domains alters direction but not the level of axonal transport of mitochondria.

ABSTRACT: Axonal transport of membranous organelles such as mitochondria is essential for neuron viability and function. How signaling mechanisms regulate or influence mitochondrial distribution and transport is still largely unknown. We observed an increase in the distal distribution of mitochondria in neurons upon the expression of pleckstrin homology (PH) domains of phospholipase Cdelta1 (PLCdelta-PH) and spectrin (spectrin-PH). Quantitative analysis of mitochondrial transport showed that specific binding of PH domains to phosphatidylinositol (4,5) bisphosphate (PtdIns(4,5)P2) but not 3' phosphorylated phosphatidylinositol species enhanced plus-end-directed transport of mitochondria two- to threefold and at the same time decreased minus-end-directed transport of mitochondria along axonal microtubules (MTs) without altering the overall level of motility. Further, the velocity and duration of mitochondrial transport plus the association of molecular motors with mitochondria remained unchanged by the expression of PH domains. Thus, PtdIns(4,5)P2-specific PH domains caused an increase in distal mitochondria by disturbing the balance of plus- and minus-end-directed transport rather than directly affecting the molecular machinery involved. Taken together our data reveal that level and directionality of transport are separable and that PtdIns(4,5)P2 has a novel role in regulation of the directionality of axonal transport of mitochondria.

SUBMITTER: De Vos KJ

PROVIDER: S-EPMC196556 | biostudies-literature | 2003 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Expression of phosphatidylinositol (4,5) bisphosphate-specific pleckstrin homology domains alters direction but not the level of axonal transport of mitochondria.

De Vos Kurt J KJ Sable Julia J Miller Kyle E KE Sheetz Michael P MP

Molecular biology of the cell 20030711 9

Axonal transport of membranous organelles such as mitochondria is essential for neuron viability and function. How signaling mechanisms regulate or influence mitochondrial distribution and transport is still largely unknown. We observed an increase in the distal distribution of mitochondria in neurons upon the expression of pleckstrin homology (PH) domains of phospholipase Cdelta1 (PLCdelta-PH) and spectrin (spectrin-PH). Quantitative analysis of mitochondrial transport showed that specific bind ...[more]

PMID: 12972553

Similar Datasets

Project description:Background:Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is an important regulator of several cellular processes and a precursor for other second messengers which are involved in cell signaling pathways. Signaling proteins preferably interact with PI(4,5)P2 through its pleckstrin homology (PH) domain. Efforts are underway to design small molecule-based antagonist, which can specifically inhibit the PI(4,5)P2/PH-domain interaction to establish an alternate strategy for the development of drug(s) for phosphoinositide signaling pathways. Methods:Surface plasmon resonance, molecular docking, circular dichroism, competitive Förster resonance energy transfer, isothermal titration calorimetric analyses and liposome pull down assay were used. Results:In this study, we employed 1,2,3-triazol-4-yl methanol containing small molecule (CIPs) as antagonists for PI(4,5)P2/PH-domain interaction and determined their inhibitory effect by using competitive-surface plasmon resonance analysis (IC50 ranges from 53 to 159 nM for PI(4,5)P2/PLC?1-PH domain binding assay). We also used phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3], phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2], PI(4,5)P2 specific PH-domains to determine binding selectivity of the compounds. Various physicochemical analyses showed that the compounds have weak affect on fluidity of the model membrane but, strongly interact with the phospholipase C ?1 (PLC?1)-PH domains. The 1,2,3-triazol-4-yl methanol moiety and nitro group of the compounds are essential for their exothermic interaction with the PH-domains. Potent compound can efficiently displace PLC?1-PH domain from plasma membrane to cytosol in A549 cells. Conclusions:Overall, our studies demonstrate that these compounds interact with the PIP-binding PH-domains and inhibit their membrane recruitment. General significance:These results suggest specific but differential binding of these compounds to the PLC?1-PH domain and emphasize the role of their structural differences in binding parameters. These triazole-based compounds could be directly used/further developed as potential inhibitor for PH domain-dependent enzyme activity.

Dataset Information

Expression of phosphatidylinositol (4,5) bisphosphate-specific pleckstrin homology domains alters direction but not the level of axonal transport of mitochondria.

Publications

Expression of phosphatidylinositol (4,5) bisphosphate-specific pleckstrin homology domains alters direction but not the level of axonal transport of mitochondria.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets