Real time imaging reveals a peroxisomal reticulum in living cells.
We have directly imaged the dynamic behavior of a variety of morphologically different peroxisomal structures in HepG2 and COS-7 cells transfected with a construct encoding GFP bearing the C-terminal peroxisomal targeting signal 1. Real time imaging revealed that moving peroxisomes interacted with each other and were engaged in transient contacts, and at higher magnification, tubular peroxisomes appeared to form a peroxisomal reticulum. Local remodeling of these structures could be observed involving the formation and detachment of tubular processes that interconnected adjacent organelles. Inhibition of cytoplasmic dynein based motility by overexpression of the dynactin subunit, dynamitin (p50), inhibited the movement of peroxisomes in vivo and interfered with the reestablishment of a uniform distribution of peroxisomes after recovery from nocodazole treatment. Isolated peroxisomes moved in vitro along microtubules in the presence of a microtubule motor fraction. Our data reveal that peroxisomal behavior in vivo is significantly more dynamic and interactive than previously thought and suggest a role for the dynein/dynactin motor in peroxisome motility.
Schrader
M
M
Department of Biology, The Johns Hopkins University, Baltimore, MD, USA. schrader@mailer.uni-marburg.de
King
S J
SJ
Stroh
T A
TA
Schroer
T A
TA
D000818:Animals; D019556:COS Cells; D002458:Cell Fractionation; D000072159:Dynactin Complex; D019084:Fluorescent Antibody Technique, Indirect; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins; D018715:Microscopy, Video; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000502:physiology / Q000648:ultrastructure; D009068:Movement; D020675:Peroxisomes / Q000502:physiology* / Q000648:ultrastructure*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
C000606361:DCTN2 protein, human; D000072159:Dynactin Complex; D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins