CRH signaling in the Central Nervous System: understanding MAPKs activation

BONFIGLIO, J. J.; SENIN, S.; MACCARRONE G.; REWERTS, C.; REFOJO, D.; TURCK, C.; HOLSBOER F.; ARZT, E.; SILBERSTEIN, S.

Los Cocos, Cordoba, Argentina.

Congreso; South American Spring Symposium in Signal Transduction and Molecular Medicine (SISTAM2010); 2010

@font-face { font-family: "Times New Roman"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; line-height: 150%; font-size: 12pt; font-family: Helvetica; }p.MsoBodyText2, li.MsoBodyText2, div.MsoBodyText2 { margin: 0cm -36pt 0.0001pt 0cm; text-align: justify; line-height: 18pt; font-size: 11pt; font-family: "Times New Roman"; }p.MsoBodyText3, li.MsoBodyText3, div.MsoBodyText3 { margin: 0cm 0cm 0.0001pt; text-align: justify; font-size: 12pt; font-family: Times; }table.MsoNormalTable { font-size: 10pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } Corticotropin-releasing hormone (CRH) is the key mediator of the neuroendocrine, autonomic and behavioral responses to stress. Our lab demonstrated that CRH, acting through its type 1 receptor (CRHR1), activates a MAPK signal transduction pathway downstream PKA in cultured pituitary corticotrophs and in vivo in specific areas of the mouse brain (hippocampal subfields and basolateral complex of the amygdala). We are exploring the signaling network that mediates MAPK activation by CRH in hippocampal cell lines using molecular and pharmacological tools combined with proteomics. We generated hippocampal HT22 clones stably expressing CRHR1. In these clones, CRH activates ERK1/2 through Rap1 and PKA (CRH 100nM; time: 1-60 min). We started to characterize the B-Raf interactome, the MAPKKK that belongs to the canonical MAPK signaling cascade in brain. Coimmunoprecipitated proteins with endogenous B-Raf were obtained from basal cell lysates of the HT22-clone2 and analyzed by LC-MALDI-MS/MS. This analysis allowed the identification of proteins of three classes: components of cytoeskeleton, chaperones, and proteins involved in mRNA metabolism and translation. These results together contribute to the understanding of the molecular mechanisms involved in CRH signaling downstream CRHR1.