Involvement of the endoplasmic reticulum in peroxisome formation.
The traditional view holds that peroxisomes are autonomous organelles multiplying by growth and division. More recently, new observations have challenged this concept. Herein, we present evidence supporting the involvement of the endoplasmic reticulum (ER) in peroxisome formation by electron microscopy, immunocytochemistry and three-dimensional image reconstruction of peroxisomes and associated compartments in mouse dendritic cells. We found the peroxisomal membrane protein Pex13p and the ATP-binding cassette transporter protein PMP70 present in specialized subdomains of the ER that were continuous with a peroxisomal reticulum from which mature peroxisomes arose. The matrix proteins catalase and thiolase were only detectable in the reticula and peroxisomes. Our results suggest the existence of a maturation pathway from the ER to peroxisomes and implicate the ER as a major source from which the peroxisomal membrane is derived.
Geuze
Hans J
HJ
Laboratory of Cell Biology, University Medical Center Utrecht and Center for Biomedical Genetics, 3584 CX Utrecht, The Netherlands. h.j.geuze@lab.azu.nl
Murk
Jean Luc
JL
Stroobants
An K
AK
Griffith
Janice M
JM
Kleijmeer
Monique J
MJ
Koster
Abraham J
AJ
Verkleij
Arie J
AJ
Distel
Ben
B
Tabak
Henk F
HF
D018528:ATP-Binding Cassette Transporters / Q000502:physiology; D000818:Animals; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000502:physiology / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000502:physiology / Q000648:ultrastructure*; D007091:Image Processing, Computer-Assisted; D008565:Membrane Proteins / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D016253:Microscopy, Immunoelectron; D020675:Peroxisomes / Q000502:physiology / Q000648:ultrastructure*
D018528:ATP-Binding Cassette Transporters; C489271:Abcd3 protein, mouse; D008565:Membrane Proteins; C491106:Pex13 protein, mouse