140 mouse brain proteins identified by Ca2+-calmodulin affinity chromatography and tandem mass spectrometry.
Calmodulin is an essential Ca2+-binding protein that binds to a variety of targets that carry out critical signaling functions. We describe the proteomic characterization of mouse brain Ca2+-calmodulin-binding proteins that were purified using calmodulin affinity chromatography. Proteins in the eluates from four different affinity chromatography experiments were identified by 1-DE and in-gel digestion followed by LC-MS/MS. Parallel experiments were performed using two related control-proteins belonging to the EF-hand family. After comparing the results from the different experiments, we were able to exclude a significant number of proteins suspected to bind in a nonspecific manner. A total of 140 putative Ca2+-calmodulin-binding proteins were identified of which 87 proteins contained calmodulin-binding motifs. Among the 87 proteins that contained calmodulin-binding motifs, 48 proteins have not previously been shown to interact with calmodulin and 39 proteins were known calmodulin-binding proteins. Many proteins with ill-defined functions were identified as well as a number of proteins that at the time of the analysis were described only as ORFs. This study provides a functional framework for studies on these previously uncharacterized proteins.
Berggård
Tord
T
Department of Protein Technology, Lund University, Sölvegatan 33, Wallenberglaboratoriet, SE-221 00 Lund, Sweden. tord.berggard@bpc.lu.se
Arrigoni
Giorgio
G
Olsson
Olof
O
Fex
Malin
M
Linse
Sara
S
James
Peter
P
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D002846:Chromatography, Affinity; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism; D053719:Tandem Mass Spectrometry
D002147:Calmodulin; D009419:Nerve Tissue Proteins; D002118:Calcium