The pro sequence of lactase-phlorizin hydrolase is required for the enzyme to reach the plasma membrane. An intramolecular chaperone?
Various cDNAs coding for part or all of human pre-pro lactase-phlorizin hydrolase (pre-proLPH) were transfected into COS cells and the subcellular location of the lactase-related proteins assessed. Only the complete proLPH reached the plasma membrane. LPH without the pro sequence, and a construct containing the pro sequence and the lactase domain of mature LPH, accumulated intracellularly; the pro sequence with no mature domain was secreted. We conclude that the pro sequence is important for LPH to be transported to the cell surface.
Oberholzer
T
T
Department of Biochemistry, Swiss Federal Institute of Technology, ETH-Zentrum, Zürich.
Mantei
N
N
Semenza
G
G
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D004792:Enzyme Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010694:Lactase-Phlorizin Hydrolase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D021382:Protein Sorting Signals / Q000502:physiology*; D014162:Transfection
D004792:Enzyme Precursors; D021382:Protein Sorting Signals; D010694:Lactase-Phlorizin Hydrolase