title: Goodpasture antigen-binding protein/ceramide transporter binds to human serum amyloid P-component and is present in brain amyloid plaques.
abstract: Serum amyloid P component (SAP) is a non-fibrillar glycoprotein belonging to the pentraxin family of the innate immune system. SAP is present in plasma, basement membranes, and amyloid deposits. This study demonstrates, for the first time, that the Goodpasture antigen-binding protein (GPBP) binds to human SAP. GPBP is a nonconventional Ser/Thr kinase for basement membrane type IV collagen. Also GPBP is found in plasma and in the extracellular matrix. In the present study, we demonstrate that GPBP specifically binds SAP in its physiological conformations, pentamers and decamers. The START domain in GPBP is important for this interaction. SAP and GPBP form complexes in blood and partly colocalize in amyloid plaques from Alzheimer disease patients. These data suggest the existence of complexes of SAP and GPBP under physiological and pathological conditions. These complexes are important for understanding basement membrane, blood physiology, and plaque formation in Alzheimer disease.
authors.affiliation: Department of Neuroscience, School of Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
authors.forename: Chiara
authors.initials: C
authors.lastname: Mencarelli
authors.forename: Gerard H
authors.initials: GH
authors.lastname: Bode
authors.forename: Mario
authors.initials: M
authors.lastname: Losen
authors.forename: Mahesh
authors.initials: M
authors.lastname: Kulharia
authors.forename: Peter C
authors.initials: PC
authors.lastname: Molenaar
authors.forename: Robert
authors.initials: R
authors.lastname: Veerhuis
authors.forename: Harry W M
authors.initials: HW
authors.lastname: Steinbusch
authors.forename: Marc H
authors.initials: MH
authors.lastname: De Baets
authors.forename: Gerry A F
authors.initials: GA
authors.lastname: Nicolaes
authors.forename: Pilar
authors.initials: P
authors.lastname: Martinez-Martinez
mesh_terms: D000544:Alzheimer Disease / Q000097:blood* / Q000235:genetics; D000818:Animals; D001921:Brain / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D046912:Multiprotein Complexes / Q000097:blood* / Q000235:genetics; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000097:blood* / Q000235:genetics; D017434:Protein Structure, Tertiary; D000683:Serum Amyloid P-Component / Q000235:genetics / Q000378:metabolism*
chemical_list: D046912:Multiprotein Complexes; D000683:Serum Amyloid P-Component; C119090:CERT1 protein, human; D017346:Protein Serine-Threonine Kinases