Regulated endosomal trafficking of Diacylglycerol lipase alpha (DAGLα) generates distinct cellular pools; implications for endocannabinoid signaling.
Diacylglycerol lipase alpha (DAGLα) generates the endocannabinoid (eCB) 2-arachidonylglycerol (2-AG) that regulates the proliferation and differentiation of neural stem cells and serves as a retrograde signaling lipid at synapses. Nothing is known about the dynamics of DAGLα expression in cells and this is important as it will govern where 2-AG can be made and released. We have developed a new construct to label DAGLα at the surface of live cells and follow its trafficking. In hippocampal neurons a cell surface pool of DAGLα co-localizes with Homer, a postsynaptic density marker. This surface pool of DAGLα is dynamic, undergoing endocytosis and recycling back to the postsynaptic membrane. A similar cycling is seen in COS-7 cells with the internalized DAGLα initially transported to EEA1 and Rab5-positive early endosomes via a clathrin-independent pathway before being transported back to the cell surface. The internalized DAGLα is present on reticular structures that co-localize with microtubules. Importantly, DAGLα cycling is a regulated process as inhibiting PKC results in a significant reduction in endocytosis. This is the first description of DAGLα cycling between the cell surface and an intracellular endosomal compartment in a manner that can regulate the level of the enzyme at the cell surface.
Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK.
Ya
Y
Zhou
Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK.
Fiona V
FV
Howell
Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK.
Oleg O
OO
Glebov
Randall Division of Cell and Molecular Biophysics, King's College London, SE1 1UL, UK.
David
D
Albrecht
Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK.
Gareth
G
Williams
Wolfson Centre for Age-Related Diseases, King's College London, SE1 1UL, UK. Electronic address: patrick.doherty@kcl.ac.uk.
Patrick
P
Doherty
D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism*; D002522:Chlorocebus aethiops; D063388:Endocannabinoids / Q000378:metabolism*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D057907:Post-Synaptic Density / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
D063388:Endocannabinoids; D011493:Protein Kinase C; D008071:Lipoprotein Lipase
2-AG; DAGLα; Endocannabinoid; Endocytosis; Endosomes; Trafficking