Protein Science
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Published online before print April 23, 2008
Protein Science, DOI: 10.1110/ps.073326608
 Copyright © 2008 The Protein Society
This Article
Right arrow Full Text (PDF)
Right arrow Supplemental Research Data
Right arrow All Versions of this Article:
ps.073326608v1
17/6/1025    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Montaville, P.
Right arrow Articles by Becker, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Montaville, P.
Right arrow Articles by Becker, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

The PIP2 binding mode of the C2 domains of rabphilin-3A

Pierre Montaville1,3, Nicolas Coudevylle1,3, Anand Radhakrishnan2, Andrei Leonov1, Markus Zweckstetter1, and Stefan Becker1

1 Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
2 Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany

(RECEIVED October 31, 2007; FINAL REVISION February 8, 2008; ACCEPTED March 10, 2008)

Phosphatidylinositol-4,5-bisphosphate (PIP2) is a key player in the neurotransmitter release process. Rabphilin-3A is a neuronal C2 domain tandem containing protein that is involved in this process. Both its C2 domains (C2A and C2B) are able to bind PIP2. The investigation of the interactions of the two C2 domains with the PIP2 headgroup IP3 (inositol-1,4,5-trisphosphate) by NMR showed that a well-defined binding site can be described on the concave surface of each domain. The binding modes of the two domains are different. The binding of IP3 to the C2A domain is strongly enhanced by Ca2+ and is characterized by a KD of 55 µM in the presence of a saturating concentration of Ca2+ (5 mM). Reciprocally, the binding of IP3 increases the apparent Ca2+ binding affinity of the C2A domain in agreement with a Target-Activated Messenger Affinity (TAMA) mechanism. The C2B domain binds IP3 in a Ca2+-independent fashion with low affinity. These different PIP2 headgroup recognition modes suggest that PIP2 is a target of the C2A domain of rabphilin-3A while this phospholipid is an effector of the C2B domain.

Keywords: C2 domain tandem; rabphilin-3A; IP3; calcium-binding protein; NMR; protein/ligand docking; HADDOCK

3 These authors contributed equally to this work.

Supplemental material: see www.proteinscience.org

Reprint requests to: Stefan Becker, Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; e-mail: sabe{at}nmr.mpibpc.mpg.de; fax: 49-551-201-2202.

Abbreviations: PIP2, phosphatidylinositol-4,5-bisphosphate; DOPIP2, 1,2-dioctanoyl-PIP2; PS, phosphatidylserine; GPS, glycerophosphoserine; CBR. Ca2+ binding region; CBL, Ca2+-binding loop; NOE, nuclear Overhauser effect; SA, simulated annealing; MD, molecular dynamics; DAG, diacylglycerol; Tr-NOESY, transfer nuclear Overhauser effect spectroscopy; STD, saturation transfer difference.

Article published online ahead of print. Article and publication date are at http://www.proteinscience.org/cgi/doi/10.1110/ps.073326608.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2008 by The Protein Society.