Structural determinants for transport of lactase phlorizin-hydrolase in the early secretory pathway as a multi-domain membrane glycoprotein

Proposed model for the folding events of nascent LPH. In the ER, partially folded LPH is interacting with calnexin/calreticulin chaperone system at domains II and IV. This interaction promotes functional folding of the whole protein which can then be arranged in a dimeric conformation mediated by regions in cytoplasmic and transmembrane sections as well as domains II and IV. The dimeric structure will then leave the ER to the Golgi apparatus.137