title: Evidence for a critical role of the tumor necrosis factor alpha convertase (TACE) in ectodomain shedding of the p75 neurotrophin receptor (p75NTR).
abstract: Protein ectodomain shedding, the proteolytic release of the extracellullar domain of membrane-tethered proteins, can dramatically affect the function of cell surface receptors, growth factors, cytokines, and other proteins. In this study, we evaluated the activities involved in ectodomain shedding of p75NTR, a neurotrophin receptor with critical roles in neuronal differentiation and survival. p75NTR is shed in a variety of cell types, including dorsal root ganglia cells and PC12 cells. In Chinese hamster ovary cells, inhibitors of the MEK/ERK and p38 MAP kinase pathways uncovered distinct signaling pathways required for the constitutive and stimulated shedding of p75NTR. Stimulated p75NTR shedding is abrogated in M2 mutant Chinese hamster ovary cells that lack functional tumor necrosis factor-alpha converting enzyme (TACE, also referred to as ADAM17) and in cells isolated from adam17-/- mice, but not in cells from adam9/12/15-/- or adam10-/- mice. Stimulated p75(NTR) shedding is strongly reduced by deletion of 15 amino acid residues in its extracellular membrane-proximal stalk domain. However, similar to other shed proteins, point mutations and overlapping shorter deletions within this region have little or no effect on shedding. Because ectodomain shedding of p75NTR releases a soluble ectodomain and could also be a prerequisite for its regulated intramembrane proteolysis, these findings may have important implications for the functional regulation of p75NTR.
authors.affiliation: Cell Biology Program, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
authors.forename: Gisela
authors.initials: G
authors.lastname: Weskamp
authors.forename: Johannes
authors.initials: J
authors.lastname: Schlöndorff
authors.forename: Lawrence
authors.initials: L
authors.lastname: Lum
authors.forename: J David
authors.initials: JD
authors.lastname: Becherer
authors.forename: Tae-Wan
authors.initials: TW
authors.lastname: Kim
authors.forename: Paul
authors.initials: P
authors.lastname: Saftig
authors.forename: Dieter
authors.initials: D
authors.lastname: Hartmann
authors.forename: Gillian
authors.initials: G
authors.lastname: Murphy
authors.forename: Carl P
authors.initials: CP
authors.lastname: Blobel
mesh_terms: D051722:ADAM Proteins; D000072198:ADAM17 Protein; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D066298:In Vitro Techniques; D020935:MAP Kinase Signaling System; D008666:Metalloendopeptidases / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009154:Mutation; D016716:PC12 Cells; D017434:Protein Structure, Tertiary; D051381:Rats; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D011994:Recombinant Proteins; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606463:Adam17 protein, mouse; C000606464:Adam17 protein, rat