Figure 6

Possible signaling pathway for carbachol-induced pigment granule dispersion in bluegill RPE. In conjunction with previous evidence, a pathway that follows carbachol and forskolin (FSK) treatment is proposed. Arrows in red represent the pathway involved in dispersion; whereas, black arrows represent the aggregation pathway. All of the mediators shown have been tested with the exception of calmodulin, which may be required for calcineurin activation [28]. The specific phosphorylated/dephosphorylated substrate(s) is(are) unknown. Abbreviations used are as follows (listed alphabetically): ATP, adenosine triphosphate; Ca²⁺ _i , intracellular free calcium ions; cAMP _i , intracellular cyclic adenosine monophosphate; DAG, diacylglycerol; FSK, forskolin; Gα _q , alpha subunit of the G_q family of GTP-binding proteins; IP ₃ , inositol trisphosphate; M _odd , muscarinic acetylcholine receptor subtype 1, 3, or 5; PIP ₂ , phosphatidyl inositol bisphosphate;PKA, cAMP-dependent protein kinase;PLC, phospholipase C.