Targeting of rough endoplasmic reticulum membrane proteins and ribosomes in invertebrate neurons.
The endoplasmic reticulum (ER) is divided into rough and smooth domains (RER and SER). The two domains share most proteins, but RER is enriched in some membrane proteins by an unknown mechanism. We studied RER protein targeting by expressing fluorescent protein fusions to ER membrane proteins in Caenorhabditis elegans. In several cell types RER and general ER proteins colocalized, but in neurons RER proteins were concentrated in the cell body, whereas general ER proteins were also found in neurites. Surprisingly RER membrane proteins diffused rapidly within the cell body, indicating they are not localized by immobilization. Ribosomes were also concentrated in the cell body, suggesting they may be in part responsible for targeting RER membrane proteins.
Rolls
Melissa M
MM
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Hall
David H
DH
Victor
Martin
M
Stelzer
Ernst H K
EH
Rapoport
Tom A
TA
D000818:Animals; D015415:Biomarkers; D017173:Caenorhabditis elegans / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D018870:Endoplasmic Reticulum, Rough / Q000378:metabolism* / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D021381:Protein Transport; D018091:Receptors, AMPA; D017470:Receptors, Glutamate / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
D015415:Biomarkers; D029742:Caenorhabditis elegans Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; D011993:Recombinant Fusion Proteins; C096470:glr-1 protein, C elegans; D049452:Green Fluorescent Proteins