Proteolytic processing of human intestinal lactase‐phlorizin hydrolase precursor is not a prerequisite for correct sorting in Madin Darby canine kidney (MDCK) cells

FEBS Letters

Luginbühl, Ursula²  Grünberg, Jürgen¹  Sterchi, Erwin E.¹ 

[1] Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Berne, CH-30212 Berne, Switzerland;The Department of Pediatrics, Faculty of Medicine, University of Berne, CH-30212 Berne, Switzerland

关键词: Lactase-phlorizin hydrolase;    Human;    Enterocyte;    Proteolytic processing;    Sorting;    Surface expression;    LPH;    lactase-phlorizine hydrolase;    TGN;    trans-Golgi network;    SDS-PAGE;    sodium dodecylsulfate-polyacrylamid-gel electrophoresis;    PBS;    phosphate buffered saline;   

DOI  :  10.1016/0014-5793(92)81476-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Maturation or lactase-phlorizin hydrolase (LPH) (EC 3.2.1.23–62) requires proteolytic processing of precursor (pro-LPH) to mature microvillus membrane enzyme (m-LPH). Subcellular site and function of this processing are unknown. We studied the processing and sorting of human LPH expressed permanently in MDCK cells. LPH was inserted into the apical membrane and small amounts were found basolateral. Of the LPH immunoprecipitated from the apical membrane, 42% was in the mature, i.e. proteoytically processed form; on the basolateral membrane it was 20%. Thus, LPH-processing occurs after sorting and is not necessary for surface expression.

【 授权许可】

Unknown