The disulfide bond in chromogranin B, which is essential for its sorting to secretory granules, is not required for its aggregation in the trans‐Golgi network

FEBS Letters

Chanat, Eric¹  Huttner, Wieland B.¹  Weiß, Ursula¹ 

[1] Institute for Neurobiology, University of Heidelberg, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany

关键词: Aggregation;    Dithiothreitol;    Granin;    Proteolysis;    Sorting;    Trans-Golgi network;    DTT;    dithiothreitol;    CgB;    chromogranin B;    SgII;    secretogranin II;    TGN;    trans-Golgi network;   

DOI  :  10.1016/0014-5793(94)00865-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Chromogranin B (secretogranin I), a protein sorted to secretory granules in many endocrine cells and neurons, undergoes selective aggregation during the sorting process in the trans-Golgi network. Reduction of the single, highly conserved intramolecular disulfide bond of chromogranin B by exposure of intact PC12 cells to the thiol reducing agent dithiothreitol has previously been shown to cause its missorting to the constitutive pathway of secretion. Using saponin perforation of membrane vesicles in aggregative buffer mimicking the milieu in the lumen of the trans-Golgi network (pH 6.4, 10 mM calcium), we show here that treatment with dithiothreitol does not prevent the aggregation of chromogranin B in this compartment. This implies that the loop in the chromogranin B polypeptide that is formed by the disulfide bond has a critical role in the membrane recognition of aggregated chromogranin B during secretory granule formation.

【 授权许可】

Unknown