TY - JOUR

T1 - Delivery of internalized ricin from endosomes to cisternal golgi elements is a discontinuous, temperature-sensitive process

AU - Van Deurs, B.

AU - Petersen, O. W.

AU - Olsnes, S.

AU - Sandvig, K.

PY - 1987/7

Y1 - 1987/7

N2 - Galactose-terminating membrane glycoproteins and glycolipids on two established human breast carcinoma cell lines were tagged at 4 °C with a ricin-horseradish peroxidase conjugate (Ri-HRP). The cells were then incubated for various periods of time at 37 or 18 °C. After fixation and diaminobenzidine cytochemistry, the compartments reached by Ri-HRP were studied by analyzing thin serial sections. In both cell types a highly pleomorphic endosomal system comprising vacuolar elements as well as smaller, sometimes branched, tubular elements (tubular endosomes) was revealed at both 37 and 18 °C. At 37 °C Ri-HRP was consistently observed in flattened cisterns of the Golgi region in 30-40% of the Golgi complexes examined after 30-60 min of incubation. However, no Ri-HRP reached such Golgi elements at 18 °C, even after incubation for 180 min. Moreover, at 18 °C the ability of ricin to inhibit protein synthesis was virtually abolished, whereas the effect of diphtheria toxin was reduced much less. Following incubation with a monovalent transferrin-HRP conjugate or with unconjugated HRP, no labeling of cisternal Golgi elements was detected. These data indicate that delivery of galactose-terminating membrane molecules from endosomes to the Golgi complex is a discontinuous, temperature-sensitive process and that this process may be required for optimal ricin A-chain translocation.

AB - Galactose-terminating membrane glycoproteins and glycolipids on two established human breast carcinoma cell lines were tagged at 4 °C with a ricin-horseradish peroxidase conjugate (Ri-HRP). The cells were then incubated for various periods of time at 37 or 18 °C. After fixation and diaminobenzidine cytochemistry, the compartments reached by Ri-HRP were studied by analyzing thin serial sections. In both cell types a highly pleomorphic endosomal system comprising vacuolar elements as well as smaller, sometimes branched, tubular elements (tubular endosomes) was revealed at both 37 and 18 °C. At 37 °C Ri-HRP was consistently observed in flattened cisterns of the Golgi region in 30-40% of the Golgi complexes examined after 30-60 min of incubation. However, no Ri-HRP reached such Golgi elements at 18 °C, even after incubation for 180 min. Moreover, at 18 °C the ability of ricin to inhibit protein synthesis was virtually abolished, whereas the effect of diphtheria toxin was reduced much less. Following incubation with a monovalent transferrin-HRP conjugate or with unconjugated HRP, no labeling of cisternal Golgi elements was detected. These data indicate that delivery of galactose-terminating membrane molecules from endosomes to the Golgi complex is a discontinuous, temperature-sensitive process and that this process may be required for optimal ricin A-chain translocation.

UR - http://www.scopus.com/inward/record.url?scp=0023239830&partnerID=8YFLogxK

U2 - 10.1016/0014-4827(87)90257-6

DO - 10.1016/0014-4827(87)90257-6

M3 - Journal article

C2 - 3622628

AN - SCOPUS:0023239830

VL - 171

SP - 137

EP - 152

JO - Experimental Cell Research

JF - Experimental Cell Research

SN - 0014-4827

IS - 1

ER -