Figures & data
Figure 1 Simplified overview of Rab 7, Rab7b function and receptor trafficking. Rab7b is localized to late endosomes (LE) and lysosomes (Lys), and to TGN/Golgi, directing the transport between these compartments. EGF binds its receptor EGFR on the plasma membrane, this leads to dimerization which initiate a signaling cascade, and internalization of the complex to early endosomes where it is still able to signal. EGFR is then taken into the the lumen of MVBs of late endosomes and lysosomes for degradation. Rab7, (but not Rab7b) regulates these steps of transport from early endosomes to late endosomes and lysosomes. TLR4 associated with MD2 at the endoplasmic reticulum (ER), and it is transported through the Golgi to the plasma membrane. When it is activated by the LPS/CD14, it starts the signaling and it is internalized in early endosomes and degraded in late endosomes and lysosomes. TLR9 is normally resident in the ER. After cell activation, it is transported to the endolysosomal compartment, passing through the Golgi. In these compartments, the receptor is proteolytically cleaved, allowing the activation of the signaling cascade after binding the endocytosed ligand (CpG DNA).
