Release of a membrane-bound death domain by gamma-secretase processing of the p75NTR homolog NRADD.
Neurotrophin receptor alike death domain protein (NRADD) is a death-receptor-like protein with a unique ectodomain and an intracellular domain homologous to p75(NTR). Expression of NRADD results in apoptosis, but only in certain cell types. This paper characterizes the expression and proteolytic processing of the mature 55 kDa glycoprotein. N-terminally truncated NRADD is processed by a gamma-secretase activity that requires presenilins and has the same susceptibility to gamma-secretase inhibitors as the secretion of amyloid beta (A beta). The ectodomain of endogenous NRADD is shed by activation of metalloproteinases. Inhibitor studies provide evidence that NRADD is cleaved in two steps typical of regulated intramembrane proteolysis (RIP). Inhibition of gamma-secretase abrogates both the production of the soluble intracellular domain of NRADD and the appearance of NRADD in subnuclear structures. Thus, solubilized death domains with close homology to p75(NTR) might have a nuclear function. Furthermore, presenilin deficiency leads to abnormally glycosylated NRADD and overexpression of presenilin 2 inhibits NRADD maturation, which is dependent on the putative active site residue D366 but not on gamma-secretase activity. Our results demonstrate that NRADD is an additional gamma-secretase substrate and suggest that drugs against Alzheimer's disease will need to target gamma-secretase in a substrate-specific manner.
Department of Pathology, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
Kavitha
K
Gowrishankar
Michael G
MG
Zeidler
Claudius
C
Vincenz
D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000544:Alzheimer Disease / Q000378:metabolism; D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D016282:Aspartic Acid Endopeptidases; D016466:CHO Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D006224:Cricetinae; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006031:Glycosylation; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D041681:NIH 3T3 Cells; D009928:Organ Specificity; D053766:Presenilin-2; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary / Q000502:physiology; D020800:Receptor, Nerve Growth Factor; D053218:Receptors, Death Domain; D017475:Receptors, Nerve Growth Factor / Q000235:genetics*
D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C480683:Nradd protein, mouse; C508861:PSEN2 protein, human; D053766:Presenilin-2; D020033:Protein Isoforms; D020800:Receptor, Nerve Growth Factor; D053218:Receptors, Death Domain; D017475:Receptors, Nerve Growth Factor; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human; C509282:Bace1 protein, mouse