Goodpasture Antigen-binding Protein/Ceramide Transporter Binds to Human Serum Amyloid P-Component and Is Present in Brain Amyloid Plaques

Chiara Mencarelli, Gerard H. Bode, Mario Losen, Mahesh Kulharia, Peter C. Molenaar, Robert Veerhuis, Harry W. M. Steinbusch, Marc H. De Baets, Gerry A. F. Nicolaes, Pilar Martinez-Martinez*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


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.
Original languageEnglish
Pages (from-to)14897-14911
JournalJournal of Biological Chemistry
Issue number18
Publication statusPublished - 27 Apr 2012

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