Linking membrane microdomains to the cytoskeleton: regulation of the lateral mobility of reggie-1/flotillin-2 by interaction with actin.
The reggies/flotillins are oligomeric scaffolding proteins for membrane microdomains. We show here that reggie-1/flotillin-2 microdomains are organized along cortical F-actin in several cell types. Interaction with F-actin is mediated by the SPFH domain as shown by in vivo co-localization and in vitro binding experiments. Reggie-1/flotillin-2 microdomains form independent of actin, but disruption or stabilization of the actin cytoskeleton modulate the lateral mobility of reggie-1/flotillin-2 as shown by FRAP. Furthermore, reggie/flotillin microdomains can efficiently be immobilized by actin polymerisation, while exchange of reggie-1/flotillin-2 molecules between microdomains is enhanced by actin disruption as shown by tracking of individual microdomains using TIRF microscopy.
Langhorst
Matthias F
MF
Department of Biology, University of Konstanz, Universitaetsstrasse 10, D-78457 Konstanz, Germany. Mattiaslanghorst@email.de
Solis
Gonzalo P
GP
Hannbeck
Sylvia
S
Plattner
Helmut
H
Stuermer
Claudia A O
CA
D000199:Actins / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D045744:Cell Line, Tumor; D003599:Cytoskeleton / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D011485:Protein Binding; D021381:Protein Transport
D000199:Actins; D008565:Membrane Proteins; C106354:flotillins