Detection of novel intracellular agonist responsive pools of phosphatidylinositol 3,4-bisphosphate using the TAPP1 pleckstrin homology domain in immunoelectron microscopy

Watt, Stephen A.; Kimber, Wendy A.; Fleming, Ian N.; Leslie, Nicholas R.; Downes, C P; Lucocq, John M.

doi:10.1042/bj20031397

Cited by 62 publications

(61 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One possibility is that an accessory molecule may be required for endosomal localisation, thus leading to mislocalisation of overexpressed proteins. Alternatively, the phosphoinositide profile of the secretory pathway is richer than previously anticipated, as suggested by recent electron microscopic studies (Watt et al, 2004;Watt et al, 2002). Interestingly, overexpression of MTM1 in muscle cell lines hydrolyses endosomal PtdIns3P to the point at which binding of EEA1 is lost, but the cellular mass of PtdIns3P is little changed (Chaussade et al, 2003).…”

Section: Discussionmentioning

confidence: 76%

Analysis of phosphoinositide binding domain properties within the myotubularin-related protein MTMR3

Lorenzo

Urbé

Clague

2005

Journal of Cell Science

View full text Add to dashboard Cite

The myotubularins are a large family of phosphoinositidespecific phosphatases with substrate specificity for PtdIns3P and PtdIns(3,5)P 2 . In addition to an N-terminal PH-GRAM (PH-G) domain and a signature catalytic domain shared with other family members, MTMR3 contains a C-terminal FYVE domain. We show that the FYVE domain of MTMR3 is atypical in that it neither confers endosomal localisation nor binds to the lipid PtdIns3P. Furthermore the FYVE domain is not required for in vitro enzyme activity of MTMR3. In contrast, the PH-GRAM domain is able to bind to phosphoinositide lipids, of which the allosteric regulator PtdIns5P is the preferred partner. Consequently, generation of PtdIns5P at the plasma membrane by ectopic expression of the bacterial phosphatase IpgD leads to a translocation of MTMR3 that requires the PH-G domain. Deletion of the PH-G domain leads to loss of activity of MTMR3 in vitro, and surprisingly, when combined with an active site mutation, accumulates the protein on the Golgi complex.

show abstract

Section: Discussionmentioning

confidence: 76%

Analysis of phosphoinositide binding domain properties within the myotubularin-related protein MTMR3

Lorenzo

Urbé

Clague

2005

Journal of Cell Science

View full text Add to dashboard Cite

show abstract

“…PtdIns(3,4)P 2 accumulates both at the plasma membrane and on intracellular membranes, including tubulo-vesicular structures, the endoplasmic reticulum, and multivesicular bodies upon agonist stimulation (Watt et al, 2004). We reasoned that overexpression of the 4-phosphatase may catalyze the hydrolysis of PtdIns(3,4)P 2 , forming PtdIns(3)P on endosomal membranes.…”

Section: Expression Of the Catalytically Active 4-phosphatase Rescuesmentioning

confidence: 99%

The Type Iα Inositol Polyphosphate 4-Phosphatase Generates and Terminates Phosphoinositide 3-Kinase Signals on Endosomes and the Plasma Membrane

Ivetac

Munday

Kisseleva

et al. 2005

MBoC

View full text Add to dashboard Cite

Endosomal trafficking is regulated by the recruitment of effector proteins to phosphatidylinositol 3-phosphate [PtdIns(3)P] on early endosomes. At the plasma membrane, phosphatidylinositol-(3,4)-bisphosphate [PtdIns(3,4)P2] binds the pleckstrin homology (PH) domain-containing proteins Akt and TAPP1. Type Iα inositol polyphosphate 4-phosphatase (4-phosphatase) dephosphorylates PtdIns(3,4)P2, forming PtdIns(3)P, but its subcellular localization is unknown. We report here in quiescent cells, the 4-phosphatase colocalized with early and recycling endosomes. On growth factor stimulation, 4-phosphatase endosomal localization persisted, but in addition the 4-phosphatase localized at the plasma membrane. Overexpression of the 4-phosphatase in serum-stimulated cells increased cellular PtdIns(3)P levels and prevented wortmannin-induced endosomal dilatation. Furthermore, mouse embryonic fibroblasts from homozygous Weeble mice, which have a mutation in the type I 4-phosphatase, exhibited dilated early endosomes. 4-Phosphatase translocation to the plasma membrane upon growth factor stimulation inhibited the recruitment of the TAPP1 PH domain. The 4-phosphatase contains C2 domains, which bound PtdIns(3,4)P2, and C2-domain-deletion mutants lost PtdIns(3,4)P2 4-phosphatase activity, did not localize to endosomes or inhibit TAPP1 PH domain membrane recruitment. The 4-phosphatase therefore both generates and terminates phosphoinositide 3-kinase signals at distinct subcellular locations.

show abstract

“…Accumulation of PtdIns(3,4,5)P 3 is usually accompanied by the production of PtdIns(3,4)P 2 (Kimber et al, 2002;Van der Kaay et al, 1999;Watt et al, 2004), due mainly to the actions of 5-phosphatases, such as SHIP-1 and SHIP-2 (Sly et al, 2003). These lipids are involved in the regulation of numerous cellular processes, such as cell survival, proliferation, growth and motility and are thought to have roles in the progression of cancer and in inflammatory and immune cell signaling.…”

Section: Introductionmentioning

confidence: 99%

Localization of agonist-sensitive PtdIns(3,4,5)P3 reveals a nuclear pool that is insensitive to PTEN expression

Lindsay

McCoull

Davidson

et al. 2006

Journal of Cell Science

Self Cite

124

View full text Add to dashboard Cite

Phosphatidylinositol (3,4,5) trisphosphate [PtdIns(3,4,5)P3] is a lipid second messenger, produced by Type I phosphoinositide 3-kinases (PI 3-kinases), which mediates intracellular responses to many growth factors. Although PI 3-kinases are implicated in events at both the plasma membrane and intracellular sites, including the nucleus, direct evidence for the occurrence of PtdIns(3,4,5)P3 at non-plasma membrane locations is limited. We made use of the pleckstrin homology (PH) domain of general receptor for phosphoinositides (Grp1) to detect PtdIns(3,4,5)P3 in an on-section labeling approach by quantitative immunogold electron microscopy. Swiss 3T3 cells contained low levels of PtdIns(3,4,5)P3 that increased up to 15-fold upon stimulation with platelet-derived growth factor (PDGF). The signal was sensitive to PI 3-kinase inhibitors and present mainly at plasma membranes, including lamellipodia, and in a surprisingly large pool within the nuclear matrix. Comparatively little labeling was observed in endomembranes. A similar distribution of PtdIns(3,4,5)P3 was observed in U87MG cells, which lack the PtdIns(3,4,5)P3 phosphatase, PTEN. Re-expression of PTEN into U87MG cells ablated plasma membrane PtdIns(3,4,5)P3, but not the nuclear pool of this lipid even when PTEN was targeted to nuclei. These data have important implications for the versatility of PI 3-kinase signaling and for the proposed functions of PTEN in the nucleus.

show abstract

Detection of novel intracellular agonist responsive pools of phosphatidylinositol 3,4-bisphosphate using the TAPP1 pleckstrin homology domain in immunoelectron microscopy

Cited by 62 publications

References 57 publications

Analysis of phosphoinositide binding domain properties within the myotubularin-related protein MTMR3

Analysis of phosphoinositide binding domain properties within the myotubularin-related protein MTMR3

The Type Iα Inositol Polyphosphate 4-Phosphatase Generates and Terminates Phosphoinositide 3-Kinase Signals on Endosomes and the Plasma Membrane

Localization of agonist-sensitive PtdIns(3,4,5)P3 reveals a nuclear pool that is insensitive to PTEN expression

Contact Info

Product

Resources

About