A FRET map of membrane anchors suggests distinct microdomains of heterotrimeric G proteins

Daniel Abankwa, H Vogel

Tutkimustuotos: LehtiartikkeliArtikkeliTieteellinenvertaisarvioitu

41 Sitaatiot (Scopus)

Abstrakti

The standard model of heterotrimeric G protein signaling postulates a dissociation of G alpha and G beta gamma subunits after activation. We hypothesized that the different combination of lipid-modifications on G alpha and G alpha beta gamma subunits directs them into different microdomains. By characterizing rapidly and at high sensitivity 38 fluorescence resonance energy transfer (FRET) pairs of heterotrimeric-G-protein constructs, we defined their microdomains in relation to each other, free from the constraints of the raft/non-raft dualism. We estimated that in a cell similar to 30% of these membrane-anchored proteins are mostly clustered in 340016,200 copies of 30-nm microdomains. We found that the membrane anchors of G alpha and G alpha beta gamma subunits of both the G(i/o) and G(q) family co-cluster differently with microdomain markers. Moreover, anchors of the G alpha(i/o) and G alpha(q) subunits co-clustered only weakly, whereas constructs that contained the anchors of the corresponding heterotrimers co-clustered considerably, suggesting the existence of at least three types of microdomain. Finally, FRET experiments with full-length heterotrimeric G proteins confirmed that the inactive, heterotrimerized G alpha subunit is in microdomains shared by heterotrimers from different subclasses, from where it displaces upon activation into a membrane-anchor- and subclass-specific microdomain.
AlkuperäiskieliEi tiedossa
Sivut2953–2962
Sivumäärä10
JulkaisuJournal of Cell Science
Vuosikerta120
Numero16
DOI - pysyväislinkit
TilaJulkaistu - 2007
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

Keywords

  • FRET
  • heterotrimeric G protein
  • microdomain
  • nanodomain
  • raft

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