FAM55B Activators

FAM55B function through various signaling pathways to modulate its activity via phosphorylation. Forskolin is one such activator, which by elevating intracellular levels of cyclic AMP (cAMP), leads to the activation of protein kinase A (PKA). The activation of PKA can directly result in the phosphorylation of FAM55B, altering its conformation and interaction dynamics to activate it. In a similar vein, Dibutyryl-cAMP, a cell-permeable analog of cAMP, also activates PKA, which then phosphorylates and activates FAM55B. Additionally, agents like Phorbol 12-myristate 13-acetate (PMA) engage with protein kinase C (PKC) to phosphorylate FAM55B at specific serine or threonine residues, which is another route to its activation.

Ionomycin, by functioning as a calcium ionophore, increases the intracellular concentration of calcium, which can activate calcium-dependent protein kinases that are capable of phosphorylating FAM55B. The increased calcium levels can also indirectly lead to the activation of PKC via the production of diacylglycerol (DAG) in the phospholipase C (PLC) pathway, which then contributes to FAM55B activation. Furthermore, the modulation of intracellular signaling through the inhibition of protein phosphatases by compounds like Calyculin A and Okadaic Acid results in the sustained phosphorylation and consequent activation of FAM55B by preventing its dephosphorylation. This is complemented by the action of growth factors such as Epidermal Growth Factor (EGF), which through its receptor EGFR, activates downstream kinases that target FAM55B. Insulin also activates its receptor pathway leading to the activation of kinases like AKT that phosphorylate FAM55B. Additionally, Anisomycin, by activating MAPK kinases, and Bradykinin, through the activation of PLC, contribute to the phosphorylation landscape that governs FAM55B activation. Hydrogen Peroxide and Zinc Pyrithione can modulate kinase activity through oxidative mechanisms and metalloenzyme modulation, further impacting the phosphorylation state of FAM55B.