TMEM106C Activators

Chemical activators of TMEM106C can utilize various pathways to achieve functional activation. Phorbol 12-myristate 13-acetate (PMA) taps into the protein kinase C (PKC) axis, phosphorylating TMEM106C and turning on its activity. Ionomycin raises intracellular calcium, which triggers calcium-dependent kinases that target TMEM106C for activation. Similarly, Thapsigargin disrupts calcium homeostasis by hindering the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA), resulting in an increase of cytosolic calcium that activates kinases capable of phosphorylating TMEM106C. Forskolin leverages the adenylyl cyclase pathway, culminating in cAMP elevation and PKA activation, which then phosphorylates and activates TMEM106C. This cAMP-dependent pathway is also exploited by Dibutyryl-cAMP and 8-Br-cAMP, both of which are analogs of cAMP and activate PKA, leading to the activation of TMEM106C.

In addition to these pathways, Bryostatin 1 modulates PKC, impacting TMEM106C phosphorylation and activation. Okadaic Acid, by selectively inhibiting protein phosphatases 1 and 2A, maintains TMEM106C in a phosphorylated, active state. Anisomycin activates stress-activated protein kinases, which then can phosphorylate and activate TMEM106C. Sphingosine is metabolized to sphingosine-1-phosphate, which in turn activates kinases that lead to the phosphorylation and activation of TMEM106C. Calyculin A also inhibits protein phosphatases, which prevents dephosphorylation and ensures TMEM106C remains active. Lastly, Epigallocatechin gallate (EGCG) can increase cAMP levels by inhibiting phosphodiesterases, thereby activating PKA and leading to the phosphorylation and activation of TMEM106C. Collectively, these chemicals engage different cellular signaling cascades that converge on the phosphorylation state of TMEM106C, culminating in its functional activation.