title: Cleavage of p75 neurotrophin receptor by alpha-secretase and gamma-secretase requires specific receptor domains.
abstract: The p75 neurotrophin receptor (p75(NTR)), a member of the tumor necrosis factor superfamily of receptors, undergoes multiple proteolytic cleavage events. These events are initiated by an alpha-secretase-mediated release of the extracellular domain followed by a gamma-secretase-mediated intramembrane cleavage. However, the specific determinants of p75(NTR) cleavage events are unknown. Many other substrates of gamma-secretase cleavage have been identified, including Notch, amyloid precursor protein, and ErbB4, indicating there is broad substrate recognition by gamma-secretase. Using a series of deletion mutations and chimeric receptors of p75(NTR) and the related Fas receptor, we have identified domains that are essential for p75(NTR) proteolysis. The initial alpha-secretase cleavage was extracellular to the transmembrane domain. Unfortunately, deletion mutants were not capable of defining the requirements of ectodomain shedding. Although this cleavage is promiscuous with respect to amino acid sequence, its position with respect to the transmembrane domain is invariant. The generation of chimeric receptors exchanging different domains of noncleavable Fas receptor with p75(NTR), however, revealed that a discrete domain above the membrane is sufficient for efficient cleavage of p75(NTR). Mass spectrometric analysis confirmed the cleavage can occur with a truncated p75(NTR) displaying only 15 extracellular amino acids in the stalk region.
authors.affiliation: Molecular Neurobiology Program, Skirball Institute for Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Niccolò
authors.initials: N
authors.lastname: Zampieri
authors.forename: Chong-Feng
authors.initials: CF
authors.lastname: Xu
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Neubert
authors.forename: Moses V
authors.initials: MV
authors.lastname: Chao
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005727:Ganglia, Spinal / Q000378:metabolism; D017353:Gene Deletion; D006801:Humans; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D016716:PC12 Cells; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D066247:Receptor, ErbB-4; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000737:chemistry / Q000378:metabolism*; D051880:Receptors, Notch; D012583:Schwann Cells / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000596:Amino Acids; D016564:Amyloid beta-Protein Precursor; D017077:Culture Media, Conditioned; D008565:Membrane Proteins; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D051880:Receptors, Notch; C587689:ERBB4 protein, human; D066246:ErbB Receptors; C587691:Erbb4 protein, rat; D066247:Receptor, ErbB-4; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human