Collagen VII maintains proteostasis in dermal fibroblasts by scaffolding TANGO1 cargo

•Absent or mutant type VII collagen (C7) leads to disrupted proteostasis in dermal fibroblasts characterized by intracellular protein accumulation, inefficient secretion, and increased cellular stress, resulting in activation of TGFβ signaling.•ER-Golgi traffic and secretion of the extracellular matrix (ECM)-associated proteins tissue transglutaminase (TGM2), thrombospondin-1 (TSP1), and type XII collagen (C12) can associate with either C7 or type I collagen in dermal fibroblasts.•We show that C7 acts as a scaffold to load TANGO1 mediated COPII carriers by binding both TANGO1 and COPII cargo.•Our data suggest that some components of ECM co-assemble in the ER and are exported as a unit.