Calmodulin-binding proteome in the brain.

Calcium dyshomeostasis is involved in neuropathological conditions such as traumatic brain injury (TBI), stroke, and neurodegenerative diseases. Under such conditions in the brain, calmodulin (CaM), a Ca(2+) sensor, mediates critical signaling functions through binding and regulating a diverse population of downstream targets referred to as calmodulin-binding proteins (CaMBPs). We developed a CaM-affinity capture method followed by reversed-phase liquid chromatography tandem mass spectrometry (RPLC-MSMS) to study the calcium-dependent CaM-binding proteome in rat brain. A total of 69 potential CaMBPs were identified by this proteomic technique, of which 26 were known CaMBPs and 43 were putative novel CaMBPs. This study shows that the CaM-affinity capture when coupled with tandem mass spectrometry may serve as an effective tool toward constructing a brain CaM-binding proteomic network. The general methods described here can be applied to study possible alternations of calmodulin-binding proteome in neurological, neurodegenerative, and psychiatric disorders.