SORLA-Dependent and -Independent Functions for PACS1 in Control of Amyloidogenic Processes

作者：Burgert Tilman; Schmidt Vanessa; Caglayan Safak; Lin Fuyu; Fuchtbauer Annette; Fuchtbauer Ernst Martin; Nykjaer Anders; Carlo Anne Sophie; Willnow Thomas E^*

来源：Molecular and Cellular Biology, 2013, 33(21): 4308-4320.

DOI：10.1128/MCB.00628-13

Sorting-related receptor with A-type repeats (SORLA) is a sorting receptor for the amyloid precursor protein (APP) that prevents breakdown of APP into A beta peptides, a hallmark of Alzheimer's disease (AD). Several cytosolic adaptors have been shown to interact with the cytoplasmic domain of SORLA, thereby controlling intracellular routing of SORLA/APP complexes in cell lines. However, the relevance of adaptor-mediated sorting of SORLA for amyloidogenic processes in vivo remained unexplored. We focused on the interaction of SORLA with phosphofurin acidic cluster sorting protein 1 (PACS1), an adaptor that shuttles proteins between the trans-Golgi network (TGN) and endosomes. By studying PACS1 knockdown in neuronal cell lines and investigating transgenic mice expressing a PACS1-binding-defective mutant form of SORLA, we found that disruption of SORLA and PACS1 interaction results in the inability of SORLA/APP complexes to sort to the TGN in neurons and in increased APP processing in the brain. Loss of PACS1 also impairs the proper expression of the cation-independent mannose 6-phosphate receptor and its target cathepsin B, a protease that breaks down A beta. Thus, our data identified the importance of PACS1-dependent protein sorting for amyloidogenic-burden control via both SORLA-dependent and SORLA-independent mechanisms.

• 出版日期2013-11