Fig. 4
From: RNA binding protein SAMD4: current knowledge and future perspectives
Molecular mechanisms of SAMD4 protein family members of biological functions. From the left to right, the figure describes the molecular mechanisms of SAMD4 family in cytoplasmic foci formation, mRNA decay and translation repression. After glutamate binds to NMDA receptor, mRNA-silencing foci (S foci) are rapidly disassembled and the repressed mRNA is instantaneously released to initiate the translation process. SAMD4 indirectly interacts with eIF4E to repress mRNA translation. SAMD4 recruits Ago1 to target mRNA to inhibit mRNA translation. SAMD4 recruits CCR4/POP2/NOT deadenylase complex to target mRNA and remove poly(A) tail at the 3’-end of mRNA through deadenylation, thus affecting mRNA destabilization and mediating mRNA degradation. The SAM domain of SAMD4 specifically binds to the SRE site in HBV RNA and triggers viral RNA degradation by recruiting CCR4/POP2/NOT deadenylase. AMPK activation by metformin and mTOR inhibition by rapamycin, Smaug1-body releases SDHB and UQCRC1 mRNAs, which are translated into proteins encoding mitochondrial enzymes and participate in the regulation of mitochondria function