Small integral membrane protein 30 (SMIM30)

SMIM30 is a conserved 59-amino acid micropeptide encoded by the LINC00998 gene, with two hydrophobic transmembrane domains and localization to both the endoplasmic reticulum and mitochondria. Functionally, SMIM30 promotes cell proliferation by enhancing the G1/S transition of the cell cycle, at least partly through stimulating the activity of the SERCA pump to reduce cytosolic calcium concentration, which activates cyclin/CDK-Rb-E2F1 signaling. The peptide also interacts with MAVS and RIG-I, inhibiting type I interferon signaling in anti-viral innate immunity. SMIM30 is notably upregulated in several malignancies—including hepatocellular carcinoma and glioblastoma—and its silencing impairs tumor growth, highlighting its potential significance as a cancer therapeutic target. Although originally annotated as a non-coding RNA, recent research demonstrates that the peptide, not the RNA, is functionally oncogenic.

Other names

SMIM30MAVI1Microprotein in antiviral immunity 1LINC00998SIM30hSMIM30Uniprot: A4D0T7

no known drugs; mechanistic hypothesis for targeting would be inhibition of SMIM30's cell cycle/proliferation role or immune modulation