In the December 2016 issue of Cannabis and Cannabinoid Research (volume 1, number 1, pp. 272–280), the article entitled CB1 Allosteric Modulator Org27569 Is an Antagonist/Inverse Agonist of ERK1/2 Signaling by Thomas F. Gamage et al., requires correction. The experiments reported in Figure 1B used a CB1 receptor construct that was N-terminally tagged with green fluorescent protein (GFP). This construct was rat CB1 (not human CB1). Additionally, this error appeared in the abstract and text of the article.
The original abstract text appeared as:
“HEK293 cells transfected with green fluorescent protein tagged hCB1 receptor were used to assess effects of Org27569 on CP55,940-induced receptor internalization…
In hCB1 HEK293 cells, CP55,940 (1 μM) treatment produced a significant increase in puncta at 20, 40, 60, and 120 min, consistent with receptor internalization.”
The text on page 273 read as:
“Cell lines were generated as previously described32 by transfection of the untagged hCB1 or N-terminally green fluorescent protein (GFP)-tagged hCB1 receptor with Lipofectamine 2000 (Life Technologies, Gaithersburg, MD).”
The text on page 274 read as:
“For internalization experiments, GFP-hCB1 HEK293 cells were plated on PDL-coated cover-slips in the 24-well format and treated with vehicle (0.2% DMSO), CP55,940 (1 μM), Org27569 (10 μM), or both for 20–120 min.”
The text on page 275 read as:
“In addition, we sought to determine if Org27569 could prevent internalization of GFP- tagged hCB1 receptors by the cannabinoid agonist CP55,940.”
The Figure 1 legend read as:
“(B) Org27569 prevented CP55,940-induced receptor internalization in HEK293 cells stably transfected with GFP-hCB1 receptor. Protein was separated by SDS-PAGE and western blots for phospho-ERK normalized to total ERK. GFP-hCB1 cells were seeded on PDL-coated cover-slips and treated with Org27569/CP55,940 or corresponding vehicle, imaged by a blinded observer, converted to grayscale and analyzed in ImageJ, which counted puncta.”
These have now been revised to read:
HEK293 cells transfected with green fluorescent protein tagged rat CB1 receptor were used to assess effects of Org27569 on CP55,940-induced receptor internalization…
In rat CB1 HEK293 cells, CP55,940 (1 μM) treatment produced a significant increase in puncta at 20, 40, 60, and 120 min, consistent with receptor internalization.
Cell lines were generated as previously described32 by transfection of the untagged hCB1 or N-terminally green fluorescent protein (GFP)-tagged rat CB1 receptor with Lipofectamine 2000 (Life Technologies, Gaithersburg, MD).
For internalization experiments, GFP-rat CB1 HEK293 cells were plated on PDL-coated cover-slips in the 24-well format and treated with vehicle (0.2% DMSO), CP55,940 (1 μM), Org27569 (10 μM), or both for 20–120 min.
In addition, we sought to determine if Org27569 could prevent internalization of GFP-tagged rat CB1 receptors by the cannabinoid agonist CP55,940.
(B) Org27569 prevented CP55,940-induced receptor internalization in HEK293 cells stably transfected with GFP-rat CB1 receptor. Protein was separated by SDS-PAGE and western blots for phospho-ERK normalized to total ERK. GFP-rat CB1 cells were seeded on PDL-coated cover-slips and treated with Org27569/CP55,940 or corresponding vehicle, imaged by a blinded observer, converted to grayscale and analyzed in ImageJ, which counted puncta.
The online version of the article has been corrected to reflect this change.
The authors apologize for this error.