Kex2 in the yeast Saccharomyces cerevisiae is a transmembrane, Ca2+-dependent serine protease of the subtilisin-like pro-protein convertase (SPC) family with specificity for cleavage after paired basic amino acids. At steady state, Kex2 is predominantly localized in late Golgi compartments and initiates the proteolytic maturation of pro-protein precursors that transit the distal secretory pathway. However, Kex2 localization is not static, and its itinerary apparently involves transiting out of the late Golgi and cycling back from post-Golgi endosomal compartments during its lifetime. We tested whether the endocytic pathway could deliver small molecules to Kex2 from the extracellular medium. Here we report that intramolecularly quenched fluorogenic substrates taken up into intact yeast revealed fluorescence due to specific cleavage by Kex2 protease in endosomal compartments. Furthermore, the endocytic delivery of protease inhibitors interfered with Kex2 activity for precursor protein processing. These observations reveal that the endocytic pathway does intersect with the cycling itinerary of active Kex2 protease. This strategy of endocytic drug delivery has implications for modulating SPC protease activity needed for hormone, toxin and viral glycoprotein precursor processing in human cells.
Skip Nav Destination
Article navigation
July 1999
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Research Article|
July 08 1999
Endocytic delivery of intramolecularly quenched substrates and inhibitors to the intracellular yeast Kex2 protease1
M. Kerstin HENKEL;
M. Kerstin HENKEL
2
*Department of Cellular and Structural Biology and CU Cancer Center, University of Colorado Health Sciences Center, Box B111, 4200 East Ninth Avenue, Denver, CO 80262, U.S.A.
Search for other works by this author on:
Gregory POTT;
Gregory POTT
*Department of Cellular and Structural Biology and CU Cancer Center, University of Colorado Health Sciences Center, Box B111, 4200 East Ninth Avenue, Denver, CO 80262, U.S.A.
Search for other works by this author on:
Andreas W. HENKEL;
Andreas W. HENKEL
2
*Department of Cellular and Structural Biology and CU Cancer Center, University of Colorado Health Sciences Center, Box B111, 4200 East Ninth Avenue, Denver, CO 80262, U.S.A.
Search for other works by this author on:
Luiz JULIANO;
Luiz JULIANO
†Department of Biophysics, Escola Paulista de Medicina, Sao Paulo 04044-020, Brazil
Search for other works by this author on:
Chih-Min KAM;
Chih-Min KAM
‡School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, U.S.A.
Search for other works by this author on:
James C. POWERS;
James C. POWERS
‡School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, U.S.A.
Search for other works by this author on:
Alex FRANZUSOFF
Alex FRANZUSOFF
3
*Department of Cellular and Structural Biology and CU Cancer Center, University of Colorado Health Sciences Center, Box B111, 4200 East Ninth Avenue, Denver, CO 80262, U.S.A.
3To whom correspondence should be addressed (Alex.Franzusoff@UCHSC.Edu).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
January 27 1999
Revision Received:
April 06 1999
Accepted:
May 05 1999
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London © 1999
1999
Biochem J (1999) 341 (2): 445–452.
Article history
Received:
January 27 1999
Revision Received:
April 06 1999
Accepted:
May 05 1999
Citation
M. Kerstin HENKEL, Gregory POTT, Andreas W. HENKEL, Luiz JULIANO, Chih-Min KAM, James C. POWERS, Alex FRANZUSOFF; Endocytic delivery of intramolecularly quenched substrates and inhibitors to the intracellular yeast Kex2 protease1. Biochem J 15 July 1999; 341 (2): 445–452. doi: https://doi.org/10.1042/bj3410445
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.