I am learning vesicular transport of LDL endocytosis. I understand as pH of the endosome is lower (around 6.0) than cytosol (around 7.2) due to the H+ pump, so LDL disassembles from the LDL receptor at the endosome.(wiki)
What I don't understand is how cholesterol can be effectively separated from the empty LDL receptors in the endosome, as cholesterol clusters at the central region of the endosome but the receptors cluster at the tubular region (wiki) before budding (the retrieval/recycling pathway to plasma membrane).
My current thought is cholesterol cluster is too large to get into the narrow tubular region. But I cannot find information about how empty LDL receptors can be directed to the tubular region for COP-I mediated retrieval.
Please correct me if I have made anything wrong.