Imaging metabolism of phosphatidylinositol 4,5-bisphosphate in T-cell GM1-enriched domains containing Ras proteins.
2003 (English)In: Experimental Cell Research, ISSN 0014-4827, E-ISSN 1090-2422, Vol. 285, no 1, 27-38 p.Article in journal (Refereed) Published
Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) and Ras proteins are involved in signalling pathways originating at the plasma membrane. The localisation and metabolism of PI(4,5)P(2) was studied in Jurkat T cells using fluorescence microscopic imaging with EGFP-tagged and antibody probes. Software was developed to objectively quantitate colocalisation and was used to show that plasma membrane PI(4,5)P(2) was enriched in lipid raft-containing patches of GM1 ganglioside, formed by crosslinking cholera toxin B-subunit (CT-B). The PI(4,5)P(2) metabolites phosphatidylinositol 3,4,5-trisphosphate and diacylglycerol appeared in plasma membrane CT-B-GM1 patches upon induction of signalling. Transferrin receptor and the CD45 tyrosine phosphatase did not colocalise with CT-B-GM1 patches, whereas the tyrosine kinase Lck, the scaffolding protein LAT, and endogenous Ras proteins did partially colocalise with CT-B-GM1 patches as did transfected EGFP-K-Ras(4B) and EGFP-H-Ras. The results demonstrate that T-cell PI(4,5)P(2) metabolism is occurring in GM1-enriched domains and that Ras proteins are present in these domains in vivo.
Place, publisher, year, edition, pages
2003. Vol. 285, no 1, 27-38 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-193099PubMedID: 12681284OAI: oai:DiVA.org:uu-193099DiVA: diva2:601322