Summary

Name SMG1
Full Name Serine/threonine-protein kinase SMG1
Synonyms SMG-1, hSMG-1, 61E3.4, Lambda/iota protein kinase C-interacting protein, Lambda-interacting protein | ATX, KIAA0421, LIP
Primary ID Q96Q15
Links - -
Type protein
Relations 4
Function Serine/threonine protein kinase involved in both mRNA surveillance and genotoxic stress response pathways. Recognizes the substrate consensus sequence [ST]-Q. Plays a central role in nonsense-mediated decay (NMD) of mRNAs containing premature stop codons by phosphorylating UPF1/RENT1. Recruited by release factors to stalled ribosomes together with SMG8 and SMG9 (forming the SMG1C protein kinase complex), and UPF1 to form the transient SURF (SMG1-UPF1-eRF1-eRF3) complex. In EJC-dependent NMD, the SURF complex associates with the exon junction complex (EJC) through UPF2 and allows the formation of an UPF1-UPF2-UPF3 surveillance complex which is believed to activate NMD. Also acts as a genotoxic stress-activated protein kinase that displays some functional overlap with ATM. Can phosphorylate p53/TP53 and is required for optimal p53/TP53 activation after cellular exposure to genotoxic stress. Its depletion leads to spontaneous DNA damage and increased sensitivity to ionizing radiation (IR). May activate PRKCI but not PRKCZ.

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Modifications Tables

Relations

Regulator Mechanism target score
+ up-regulates img/direct-activation.png phosphorylation UPF1 0.971
Publications: 3 Organism: Homo Sapiens
+ up-regulates img/direct-activation.png phosphorylation TP53 0.428
Publications: 1 Organism: Homo Sapiens