Fig. 10. A scheme summarizing the regulation of tTG functions on the cell surface by LRP1-mediated endocytosis. In LRP1-expressing cells with active endocytosis, the receptor downregulates surface tTG by internalization and targeting it to lysosomes for degradation, thereby decreasing cell-matrix adhesion and ECM crosslinking. In cells with no LRP1 or with impaired endocytosis, tTG accumulates on the surface owing to lack of internalization. For further information, see main text.