Fig. 6: iPGRMC1 is a mitochondrial matrix protein and is cleaved by mitochondrial processing peptidases. | Nature Communications

Fig. 6: iPGRMC1 is a mitochondrial matrix protein and is cleaved by mitochondrial processing peptidases.

From: Widespread stable noncanonical peptides identified by integrated analyses of ribosome profiling and ORF features

Fig. 6

a Volcano plot showing proteins enriched in iPGRMC1 co-IP lysates vs. control whole cell lysates (two-sided T-test, n = 3 independent experiments). We highlighted the bait and top interacting proteins, including MPP subunits PMPCA and PMPCB (blue), and 14-3-3 proteins (red). b, c Knocking out PMPCA or PMPCB rescues the detection (a) and the mitochondrial localization (b) of iPGRMC1. The coimmunostaining of TOMM20 was used to examine the mitochondrial localization. Scale bar, 10 μm. In control cells, the iPGRMC1 peptide shows cell membrane localization, indicated by the orange arrow. Experiments were performed three times with similar results. Source data are provided as a Source Data file. d Schematic overview of mitochondrial processing of iPGRMC1 by MPP. The upper panel shows the predicted MPP cleavage site by the R-2 motif. The lower model shows that iPGRMC1 peptides are transported into mitochondria through the translocase of the outer membrane (TOM) and the translocase of the inner membrane (TIM) complexes. After processing by MPP in the matrix, C-terminal iPGRMC1 peptides translocate to the cell membrane. The image was created with BioRender.com. e Heatmap showing differentially expressed genes in iPGRMC1 stably expressing MCF-7 cells. The cells expressing start codon-mutated ORF sequences were used as the control. Blue: down-regulated; Red: up-regulated. f Gene ontology analyses of differentially expressed genes in (e).

Back to article page