SMG1

This gene encodes a protein involved in nonsense-mediated mRNA decay (NMD) as part of the mRNA surveillance complex. The protein has kinase activity and is thought to function in NMD by phosphorylating the regulator of nonsense transcripts 1 protein. Alternatively spliced transcript variants have been described, but their full-length nature has yet to be determined. [provided by RefSeq, Mar 2013]

SMG1, Nonsense Mediated MRNA Decay Associated PI3K Related Kinase

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.

Biological Process DNA repairIEA:UniProtKB-KW
Biological Process mRNA export from nucleusManual Assertion Based On ExperimentTAS:UniProtKB
Biological Process negative regulation of macroautophagyManual Assertion Based On ExperimentIBA:GO_Central
Biological Process nuclear-transcribed mRNA catabolic process, nonsense-mediated decayManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process peptidyl-serine phosphorylationManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process phosphatidylinositol phosphate biosynthetic processManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process protein autophosphorylationManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process protein phosphorylationManual Assertion Based On ExperimentIBA:GO_Central
Biological Process regulation of response to DNA damage stimulusManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process regulation of telomere maintenanceManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process TOR signalingManual Assertion Based On ExperimentIBA:GO_Central

Nucleus
Cytoplasm
Present in the chromatoid body.

Autophosphorylated.