Membrane insertion of the FYVE domain is modulated by pH
The FYVE domain associates with phosphatidylinositol 3‐phosphate [PtdIns(3)P] in membranes of early endosomes and penetrates bilayers. Here, we detail principles of membrane anchoring and show that the FYVE domain insertion into PtdIns(3)P‐enriched membranes and membrane‐mimetics is substantially in...
Saved in:
Published in | Proteins, structure, function, and bioinformatics Vol. 76; no. 4; pp. 852 - 860 |
---|---|
Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Hoboken
Wiley Subscription Services, Inc., A Wiley Company
01.09.2009
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The FYVE domain associates with phosphatidylinositol 3‐phosphate [PtdIns(3)P] in membranes of early endosomes and penetrates bilayers. Here, we detail principles of membrane anchoring and show that the FYVE domain insertion into PtdIns(3)P‐enriched membranes and membrane‐mimetics is substantially increased in acidic conditions. The EEA1 FYVE domain binds to POPC/POPE/PtdIns(3)P vesicles with a Kd of 49 nM at pH 6.0, however associates ∼24 fold weaker at pH 8.0. The decrease in the affinity is primarily due to much faster dissociation of the protein from the bilayers in basic media. Lowering the pH enhances the interaction of the Hrs, RUFY1, Vps27p and WDFY1 FYVE domains with PtdIns(3)P‐containing membranes in vitro and in vivo, indicating that pH‐dependency is a general function of the FYVE finger family. The PtdIns(3)P binding and membrane insertion of the FYVE domain is modulated by the two adjacent His residues of the R(R/K)HHCRXCG signature motif. Mutation of either His residue abolishes the pH‐sensitivity. Both protonation of the His residues and nonspecific electrostatic contacts stabilize the FYVE domain in the lipid‐bound form, promoting its penetration and increasing the membrane residence time. Proteins 2009. © 2009 Wiley‐Liss, Inc. |
---|---|
Bibliography: | American Heart Association ArticleID:PROT22392 American Cancer Society Indiana University istex:ED489FCAFF758E150238340DC327057487BB7599 National Institutes of Health ark:/67375/WNG-CTQS9W16-1 Ju He and Mohsin Vora contributed equally to this work. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0887-3585 1097-0134 |
DOI: | 10.1002/prot.22392 |