Transcytosis of Aminopeptidase N in caco-2 cells is mediated by a Non-cytoplasmic Signal

TY - JOUR

T1 - Transcytosis of Aminopeptidase N in caco-2 cells is mediated by a Non-cytoplasmic Signal

AU - Vogel, L K

AU - Norén, Ove

AU - Sjöström, H

N1 - Keywords: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antigens, CD13; Caco-2 Cells; Cell Membrane; Golgi Apparatus; Humans; Kinetics; Molecular Sequence Data; Protein Processing, Post-Translational; Recombinant Proteins; Sequence Deletion; Sequence Homology, Amino Acid; Signal Transduction; Swine; Transfection

PY - 1995/9/26

Y1 - 1995/9/26

N2 - In Caco-2 cells, aminopeptidase N is transported to the apical membrane from the trans Golgi network by both the direct and the indirect pathway (Matter, K., Brauchbar, M., Bucher, K., and Hauri, H.-P. (1990) Cell 60, 429-437). The aim of this study was to determine the importance of the transmembrane or cytoplasmic domain of aminopeptidase N for transport of aminopeptidase N by the indirect pathway by analysis of mutated forms of aminopeptidase N recombinantly expressed in Caco-2 cells. A tail-less and two secretory forms of aminopeptidase N, all deprived of the cytoplasmic tail, were transported to the basolateral plasma membrane in proportions equivalent to the wild type enzyme. This shows that no cytoplasmic basolateral sorting signal is involved in directing aminopeptidase N to the basolateral plasma membrane. Both the wild type and the tail-less aminopeptidase N were transcytosed from the basolateral to the apical plasma membrane, whereas no transcytosis of two secretory forms could be detected, showing that the transmembrane domain is important for efficient transcytosis to take place. A significant difference in transcytosis kinetics of the human and the porcine wild type aminopeptidase N was observed. This indicates that transcytosis of aminopeptidase N from the basolateral to the apical membrane does not occur by default transport but involves an active sorting mechanism.

AB - In Caco-2 cells, aminopeptidase N is transported to the apical membrane from the trans Golgi network by both the direct and the indirect pathway (Matter, K., Brauchbar, M., Bucher, K., and Hauri, H.-P. (1990) Cell 60, 429-437). The aim of this study was to determine the importance of the transmembrane or cytoplasmic domain of aminopeptidase N for transport of aminopeptidase N by the indirect pathway by analysis of mutated forms of aminopeptidase N recombinantly expressed in Caco-2 cells. A tail-less and two secretory forms of aminopeptidase N, all deprived of the cytoplasmic tail, were transported to the basolateral plasma membrane in proportions equivalent to the wild type enzyme. This shows that no cytoplasmic basolateral sorting signal is involved in directing aminopeptidase N to the basolateral plasma membrane. Both the wild type and the tail-less aminopeptidase N were transcytosed from the basolateral to the apical plasma membrane, whereas no transcytosis of two secretory forms could be detected, showing that the transmembrane domain is important for efficient transcytosis to take place. A significant difference in transcytosis kinetics of the human and the porcine wild type aminopeptidase N was observed. This indicates that transcytosis of aminopeptidase N from the basolateral to the apical membrane does not occur by default transport but involves an active sorting mechanism.

M3 - Journal article

C2 - 7559429

SN - 0021-9258

VL - 270

SP - 22933

EP - 22938

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

IS - 39

ER -