Figure 3

Validation of protein synthesis at the EC PM. The possibility of protein synthesis at the EC PM was investigated by: expansion of translation under biological process to reveal the final over enriched function in this membranome (a); immunoblot analysis to confirm molecules involved in translation in rat lung; H, total tissue homogenates; P, EC PM fraction (b); EM of rat lungs stained with anti-tyrosyl-tRNA synthetase (TyrRS) antibody and gold particles (c) (see Materials and Method). Top panel shows mitochondria (Mt), cytosol (Cyto), and plasma membrane (arrowhead) of endothelial cells (ECs) at the luminal surface of blood vessels. Bottom panel shows both endothelial and epithelial cells. Alv, alveolar; BM, basement membrane; Lu, capillary lumen; WP, Weibel-palade bodies in ECs; and IB, lamella body in epithelial cell. IHC of human normal lung vasculature from Human Protein Atlas (d) (see Materials and Methods). EIF1G, eukaryotic translation initiation factor 1 gamma; SAP130, splicing factor 3b, 130; CA150, transcription elongation factor 1; EIF3 H, eukaryotic translation initiation 3, subunit 9; EIF2, elongation factor 2; EIF5B, eukaryotic translation initiation factor 5B; EIF2S1, eukaryotic translation initiation factor 2, subunit 1 alpha; and TyrRS, Tyrosyl-tRNA synthetase.