Dynamics of KRas on endosomes: involvement of acidic phospholipids in its association.
The endocytic compartment is emerging as a functional platform for controlling important cellular processes. We have found that ∼10 to 15% of total KRas, a protein that is frequently mutated in cancer, is present on endosomes, independent of its activation state. The dynamics of GFP-KRas wild-type (WT) and constitutively active or inactive mutants on endosomes were analyzed by fluorescence recovery after photobleaching (FRAP) microscopy. The measurements revealed an extraordinarily fast recovery of KRas WT [half-time (HT), ∼1.3 s] compared to HRas, Rab5, and EGFR, with the active KRasG12V mutant being significantly faster and more mobile (HT, ∼1 s, and ∼82% of exchangeable fraction) than the inactive KRasS17N (HT, ∼1.6 s, and ∼60% of exchangeable fraction). KRas rapidly switches from the cytoplasm to the endosomal membranes by an electrostatic interaction between its polybasic region and the endosomal acidic phospholipids, mainly phosphatidylserine.-Gelabert-Baldrich, M., Soriano-Castell, D., Calvo, M., Lu, A., Viña-Vilaseca, A., Rentero, C., Pol, A., Grinstein, S. Enrich, C., Tebar, F. Dynamics of KRas on endosomes: involvement of acidic phospholipids in its association.
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and.
Mariona
M
Gelabert-Baldrich
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and.
David
D
Soriano-Castell
Unitat de Microscopia Òptica Avançada, Facultat de Medicina, Centres Científics i Tecnològics, Universitat de Barcelona, Barcelona, Spain;
Maria
M
Calvo
Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA;
Albert
A
Lu
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and.
Arnau
A
Viña-Vilaseca
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and.
Carles
C
Rentero
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain; and.
Albert
A
Pol
Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
Sergio
S
Grinstein
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and.
Carlos
C
Enrich
Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), and tebar@ub.edu.
Francesc
F
Tebar
D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004705:Endocytosis / Q000235:genetics / Q000502:physiology; D011992:Endosomes / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D036681:Fluorescence Recovery After Photobleaching; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010743:Phospholipids / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism*
D010743:Phospholipids; D049452:Green Fluorescent Proteins; D016283:Proto-Oncogene Proteins p21(ras)
EGFR; PI3P; PS