Atomic Force Microscopy Imaging Reveals the Domain Structure of Polycystin-1

作者：Oatley Peter; Stewart Andrew P; Sandford Richard; Edwardson J Michael^*

来源：Biochemistry, 2012, 51(13): 2879-2888.

DOI：10.1021/bi300134b

Mutation of polycystin-1 (PC1) is the major cause of autosomal dominant polycystic kidney disease. PC1 has a predicted molecular mass of similar to 460 kDa comprising a long multidomain extracellular N-terminal region, 11 transmembrane regions, and a short C-terminal region. Because of its size, PC1 has proven difficult to handle biochemically, and structural information is consequently sparse. Here we have isolated wildtype PC1, and several mutants, from transfected cells by immunoaffinity chromatography and visualized individual molecules using atomic force microscopy (AFM) imaging. Full-length PC1 appeared as two unequally sized blobs by a 35 nm string. The relative sizes of the two blobs suggested that the smaller one represents the N-terminus, including the leucine-rich repeats, the first polycystic kidney disease (PKD) domain, and the C-type lectin motif, while the larger one is the C-terminus, including the receptor for egg jelly (REJ) domain, all transmembrane domains, and the cytoplasmic tail. The intervening string would then consist of a series of tandem PKD domains. The structures of the various PC1 mutants were all consistent with this model. Our results represent the first direct visualization of the structure of PC1, and reveal the architecture of the protein, with intriguing implications for its function.

• 出版日期2012-4-3
• 单位河北医科大学