Immunoglobulin‐derived polypeptides enter the regulated secretory pathway in AtT‐20 cells

FEBS Letters

Castle, J.David¹  Castle, Anna M.¹  Huang, Amy Y.¹ 

[1] Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA

关键词: Protein sorting;    Regulated secretion;    Pituitary AtT-20 cell;    Immunoglobulin;    POMC;    pro-opiomelanocortin;    ACTH;    adrenocorticotropic hormone;    KLC;    kappa light chain;    TGN;    trans-Golgi network;    VSV-G;    vesicular stomatitis virus G;   

DOI  :  10.1016/S0014-5793(98)01398-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Constitutively secreted proteins have traditionally been believed to be excluded from the regulated secretory pathway. In this work we show that kappa light chain and Fc fragment, two markers of the constitutive pathway, are present in the regulated pathway in AtT-20 cells. They colocalize with the endogenous hormone ACTH and they exhibit stimulus-dependent secretion. The Fc fragment, which undergoes intracellular transport at the same rate as the ACTH precursor POMC, enters the forming secretory granules, however, it is partially lost during granule maturation. These observations show that classic constitutive secretory markers are not excluded from the regulated secretory pathway and that efficient sorting for regulated secretion occurs above a background of proteins which enter the granules without sorting.

【 授权许可】

Unknown