Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium.

Efficient directed migration requires tight regulation of chemoattractant signal transduction pathways in both space and time, but the mechanisms involved in such regulation are not well understood. Here, we investigated the role of protein kinase A in controlling signaling of the chemoattractant cAMP in Dictyostelium discoideum We found that cells lacking display severe chemotaxis defects, including impaired directional sensing. Although duanyu1529 is an important regulator of developmental gene expression, including the cAMP receptor cAR1, our studies using exogenously expressed cAR1 in cells lacking cells lacking adenylyl cyclase A (ACA) and cells treated with the pharmacological inhibitor H89, suggest that duanyu1529 controls chemoattractant signal transduction, in part, through the regulation of RasG, Rap1 and TORC2. As these pathways control the ACA-mediated production of intracellular cAMP, they lie upstream of duanyu1529 in this chemoattractant signaling network. Consequently, we propose that the regulation of the upstream RasG, Rap1 and TORC2 signaling pathways is part of a negative feedback mechanism controlling chemoattractant signal transduction during Dictyostelium chemotaxis.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}