Fig. 1. A microprotein MAVI1 is down-regulated in response to RNA virus infection.

(A) HEK293 cells transfected with control siRNA (siCTL) or siRNA targeting genes as indicated were treated with or without VSV (2 × 10⁶ p.f.u.) for 12 hours before examining IFNB1 expression. (B) Ribo-seq, RNA-seq, and PhyloCSF for SMIM30 are shown. (C and D) The expression of IFNB1 (C) and SMIM30 (D) were examined in HEK293 cells infected with VSV (mean ± SEM, * P < 0.05, ***P < 0.001). (E and F) The expression of IFNB1 (E) and SMIM30 (F) were examined in HEK293 cells transfected with Poly (I:C) (5 μg/ml) (mean ± SEM, ***P < 0.001). (G) HEK293 cells were subjected to polysome profiling, and the expression of SMIM30 was examined. (H) Schematic representation of Flag-tagged ORF with or without 5′ or 3′UTR. aa, amino acid. (I) HEK293 cells were transfected with constructs as shown in (H), followed by immunoblotting (IB) analysis. (J) Schematic representation of Flag-tagged ORF and its mutants with the first (M1), the second (M2), or both (M1 + M2) ATG mutated. (K) HEK293 cells were transfected with constructs as shown in (J), followed by IB analysis. (L) Schematic representation of Flag tag insertion at the end of ORF {ORF-Flag [knock-in (KI)]} in HEK293 cells. (M) Genomic DNA was extracted from ORF-Flag (–KI) cells, followed by PCR analysis. The expected size is 322 bp. (N) The PCR product was subjected to Sanger sequencing. The Flag tag inserted is highlighted in light blue. (O) HEK293 cells transfected with empty vector (CTL) or ORF-FLAG, or ORF-Flag (KI) HEK293 cells were subjected to IB analysis. (P) HEK293 cells transfected with siCTL, siSMIM30#1, and siSMIM30#2 were subjected to IB analysis. (Q) HEK293 cells transfected with siCTL, siSMIM30, or SMIM30-FLAG were subjected to IB analysis.