Fig. 1
From: Modular assembly of synthetic proteins that span the plasma membrane in mammalian cells
A signal peptidase cleavage site enhances sorting out of the ER. Schematic layout of fusion proteins constructed in the study (a). Pictorial representation of receptors exiting the ER (b). COS-7 cells transfected with the plasma membrane labelled Lyn-Ceru showed a matte-like appearance (c) while those transfected with the ER labelled STIM1-mRFP showed a web-like fluorescence distribution (f inset). TM-Venus showed a web-like fluorescence distribution similar to STIM1-mRFP (d and f). Merged images illustrate resultant co-localization (e and g). COS-7 cells transfected with TLP-Venus (containing an additional signal peptidase cleavage site) had a less web-like fluorescence distribution when compared to STIM1-mRFP (h, i and k). Merged images illustrate resultant co-localization (j and l). Amino acid single letter codes PGSTGD represent proline, glycine, serine, threonine, glycine and aspartic acid, respectively. TM: transmembrane domain TLR4, TLP: fusion of TM with signal peptidase cleavage site from human immunoglobulin K, RGECO: red fluorescent genetically encoded Ca2+ indicator, ER: endoplasmic reticulum, LC: Lyn-Ceru, STIM1: stromal interaction molecule 1. Scale bars are 10 μm. Images are false colored: CFP, cyan; YFP, green; mRFP, red. All insets show zoomed regions (4x) of structures in dotted rectangles. All experiments were repeated at least 3 times