Nectin-1alpha, an immunoglobulin-like receptor involved in the formation of synapses, is a substrate for presenilin/gamma-secretase-like cleavage.
Nectin-1 is a member of the immunoglobulin superfamily and a Ca(2+)-independent adherens junction protein involved in synapse formation. Here we show that nectin-1alpha undergoes intramembrane proteolytic processing analogous to that of the Alzheimer's disease amyloid precursor protein, mediated by a presenilin (PS)-dependent gamma-secretase-like activity. 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of Chinese hamster ovary cells activated a first proteolytic event, resulting in ectodomain shedding of nectin-1alpha. Subsequent cleavage of the remaining 26-kDa membrane-anchored C-terminal fragment (CTF) was inhibited independently by three specific gamma-secretase inhibitors and by expression of the dominant negative form of PS1. The PS/gamma-secretase-like cleavage product was detected in vivo following proteasome inhibitor treatment of cells. An in vitro gamma-secretase assay confirmed the generation of a 24-kDa nectin-1alpha intracellular domain, peripherally associated with the membrane fraction. We also found nectin-1alpha to interact with the N-terminal fragment of PS1. Finally, gamma-secretase inhibition resulted in beta-catenin release from cell junctions, concomitantly with the accumulation of the 26-kDa nectin-1alpha CTF, suggesting that high levels of nectin-1alpha CTF interfere with TPA-induced remodeling of cell-cell junctions. Our results are consistent with a previously reported role for PS/gamma-secretase in adherens junction function involving cleavage of cadherins. Similar to nectin-1, other members of the immunoglobulin superfamily involved in synapse formation may also serve as substrates for PS/gamma-secretase-like intramembrane proteolytic activity.
Kim
Doo Yeon
DY
Neurobiology of Disease Laboratory, Genetics and Aging Research Unit, Center for Aging, Genetics and Neurodegeneration, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
Ingano
Laura A MacKenzie
LA
Kovacs
Dora M
DM
D022005:Adherens Junctions / Q000378:metabolism; D000595:Amino Acid Sequence; D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D015153:Blotting, Western; D016466:CHO Cells; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006224:Cricetinae; D003546:Cysteine Endopeptidases; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D005799:Genes, Dominant; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D009154:Mutation; D000075983:Nectins; D009474:Neurons / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D053764:Presenilin-1; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013569:Synapses / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection; D051176:beta Catenin
C495267:CTNNB1 protein, mouse; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D009097:Multienzyme Complexes; C000619015:Nectin1 protein, mouse; D000075983:Nectins; D053764:Presenilin-1; D015534:Trans-Activators; D051176:beta Catenin; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509282:Bace1 protein, mouse; D046988:Proteasome Endopeptidase Complex