FAM113B Activators

Chemical activators of FAM113B engage in various cellular signaling pathways to modulate its activity. Calcium Ionophore A23187 and Ionomycin serve as facilitators to increase intracellular calcium, a key second messenger in numerous signaling pathways, which directly results in the activation of FAM113B. The elevation of calcium levels within the cell leads to a cascade of events that culminate in the activation of proteins responsive to such ionic changes, including FAM113B. Thapsigargin also plays a role in raising intracellular calcium levels by inhibiting the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA), but this occurs through a different mechanism, specifically by preventing the reuptake of calcium into the sarcoplasmic/endoplasmic reticulum, thus maintaining a high concentration of cytosolic calcium that in turn activates FAM113B.

In another aspect of FAM113B regulation, Forskolin, by activating adenylate cyclase, raises the levels of cAMP in the cell. This increase in cAMP activates protein kinase A (PKA), which then proceeds to phosphorylate target proteins, including FAM113B. Similarly, Dibutyryl-cAMP (db-cAMP), a synthetic analog of cAMP, penetrates the cell membrane and activates PKA, leading to the phosphorylation of FAM113B. Phorbol 12-myristate 13-acetate (PMA) activates protein kinase C (PKC), and Bisindolylmaleimide I, under certain conditions, can also activate PKC isoforms, both pathways resulting in the phosphorylation and subsequent activation of FAM113B. Furthermore, Okadaic Acid and Calyculin A, by inhibiting protein phosphatases PP1 and PP2A, lead to the accumulation of phosphorylated proteins within the cell, thereby maintaining FAM113B in an activated state. Lastly, S-Nitroso-N-acetylpenicillamine (SNAP) releases nitric oxide which activates soluble guanylate cyclase and subsequently protein kinase G (PKG), leading to the activation of FAM113B. This ensemble of chemical activators, by modulating different molecular pathways, ensures the precise regulation of FAM113B's activity within the cell.