Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Targeting ADAM10 to lipid rafts in neuroblastoma SH-SY5Y cells impairs amyloidogenic processing of the amyloid precursor protein
AU - Harris, Benjamin
AU - Pereira, Isabel
AU - Parkin, Edward
PY - 2009/10/16
Y1 - 2009/10/16
N2 - ADAM10 (a disintegrin and metalloproteinase 10) is the principal alpha-secretase responsible for the non-amyloidogenic processing of the Alzheimer's disease (AD)-associated amyloid precursor protein (APP). A reciprocal relationship exists between non-amyloidogenic and amyloidogenic APP processing such that impaired ADAM10-mediated proteolysis of the protein serves to enhance amyloidogenic processing (by beta- and gamma-secretases) thereby elevating levels of the amyloid beta (A beta)-peptides responsible for the neuronal death observed in the AD-afflicted brain. It has previously been demonstrated that the amyloidogenic processing of APP occurs within specialized regions of the cell membrane known as lipid rafts. Conversely, ADAM10-mediated non-amyloidogenic processing is thought to occur in the non-raft region of the membrane with the majority of ADAM10 being excluded from rafts. In the current study, we hypothesized that the exclusion of ADAM10 from rafts may leave the APP substrate particularly susceptible to alternative beta-secretase cleavage within these microdomains. In order to test this hypothesis, we targeted ADAM10 to rafts by replacing its transmembrane and cytosolic regions with a glycosylphosphatidylinositol (GPI) anchor and examined the associated effects on APP proteolysis. We found that whereas wild-type ADAM10 was exclusively present in the non-raft region of the membrane where it enhanced non-amyloidogenic APP proteolysis, GPI-anchored ADAM10 was effectively targeted to rafts where it competed with beta-secretase thereby reducing amyloidogenic APP processing. These results indicate that it is the exclusion of ADAM10 from rafts rather than simply the raft localization of beta- and gamma-secretases that underlies A beta-peptide generation within these cellular structures.
AB - ADAM10 (a disintegrin and metalloproteinase 10) is the principal alpha-secretase responsible for the non-amyloidogenic processing of the Alzheimer's disease (AD)-associated amyloid precursor protein (APP). A reciprocal relationship exists between non-amyloidogenic and amyloidogenic APP processing such that impaired ADAM10-mediated proteolysis of the protein serves to enhance amyloidogenic processing (by beta- and gamma-secretases) thereby elevating levels of the amyloid beta (A beta)-peptides responsible for the neuronal death observed in the AD-afflicted brain. It has previously been demonstrated that the amyloidogenic processing of APP occurs within specialized regions of the cell membrane known as lipid rafts. Conversely, ADAM10-mediated non-amyloidogenic processing is thought to occur in the non-raft region of the membrane with the majority of ADAM10 being excluded from rafts. In the current study, we hypothesized that the exclusion of ADAM10 from rafts may leave the APP substrate particularly susceptible to alternative beta-secretase cleavage within these microdomains. In order to test this hypothesis, we targeted ADAM10 to rafts by replacing its transmembrane and cytosolic regions with a glycosylphosphatidylinositol (GPI) anchor and examined the associated effects on APP proteolysis. We found that whereas wild-type ADAM10 was exclusively present in the non-raft region of the membrane where it enhanced non-amyloidogenic APP proteolysis, GPI-anchored ADAM10 was effectively targeted to rafts where it competed with beta-secretase thereby reducing amyloidogenic APP processing. These results indicate that it is the exclusion of ADAM10 from rafts rather than simply the raft localization of beta- and gamma-secretases that underlies A beta-peptide generation within these cellular structures.
KW - ADAM Proteins
KW - Amyloid Precursor Protein Secretases
KW - Amyloid beta-Peptides
KW - Amyloid beta-Protein Precursor
KW - Aspartic Acid Endopeptidases
KW - Cell Line, Tumor
KW - Electrophoresis, Polyacrylamide Gel
KW - Enzyme-Linked Immunosorbent Assay
KW - Glycosylation
KW - Glycosylphosphatidylinositols
KW - Humans
KW - Immunoblotting
KW - Immunohistochemistry
KW - Membrane Microdomains
KW - Mutation
KW - Neuroblastoma
KW - Peptide Fragments
KW - Protease Nexins
KW - Receptors, Cell Surface
KW - Tumor Suppressor Proteins
U2 - 10.1016/j.brainres.2009.07.105
DO - 10.1016/j.brainres.2009.07.105
M3 - Journal article
C2 - 19679113
VL - 1296
SP - 203
EP - 215
JO - Brain Research
JF - Brain Research
IS - n/a
ER -