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Protein sorting in the Golgi apparatus: a consequence of maturation and triggered sorting
Author(s) -
Weiss Matthias,
Nilsson Tommy
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)02155-4
Subject(s) - golgi apparatus , robustness (evolution) , endoplasmic reticulum , sorting , microbiology and biotechnology , biology , secretory pathway , chemistry , evolutionary biology , genetics , computer science , gene , programming language
To explain how resident proteins distribute in peak‐like patterns at various positions in the secretory pathway, Glick and co‐workers postulated that resident proteins comprise different populations (termed kin populations) and that these compete with each other for entering retrograde transport carriers [Glick et al. (1997) FEBS Lett. 414, 177–181]. Using modelling and computer simulation, they could demonstrate that differences in competitiveness sufficed to generate overlapping but distinct peak‐like steady state distributions of the different kin populations across the Golgi stack. In this study, we have tested the robustness of the competition model and find that over‐expression or changes in the number of kin populations affect their overall steady state distributions. To increase the robustness of the system, we have introduced a milieu‐induced trigger for recycling. This allows for a decrease in the coupling between kin populations permitting both over‐expression as well as changes in the number of kin populations. We have also extended the model to include a Golgi to endoplasmic reticulum (ER) recycling pathway and find that only a small amount of resident proteins may recycle at any time without upsetting their observed distributions in the Golgi stack. The biological relevance of a trigger‐induced sorting mechanism and ER recycling is discussed.