Involvement of ELKS, an active zone protein, in exocytotic release from RBL-2H3 cells.
Recent studies have indicated that SNARE proteins and their accessory proteins are involved in exocytotic release in mast cells and neurotransmitter release in neuronal cells. These data suggest that a similar molecular mechanism operates in both systems. However, mast and neuronal cells are structurally very different; an active zone is found in neuronal cells. In the present study, we examined the involvement of active zone proteins during exocytosis in mast cells. We found that several active zone proteins are expressed in RBL-2H3 cells and focused on one of those proteins called ELKS. Overexpression and knockdown of ELKS caused an increase and decrease in exocytotic activity, respectively. Immunocytochemical analysis and live imaging of the expression of YFP-conjugated ELKS showed that ELKS was translocated to the plasma membrane after antigen stimulation. These results suggest that ELKS positively regulates exocytotic release in RBL-2H3 by acting on the plasma membrane upon stimulation.
Nomura
Hidehiro
H
Nagoya City University, Tanabe-dori, Mizuho-ku, Japan.
Ohtsuka
Toshihisa
T
Tadokoro
Satoshi
S
Tanaka
Masahiko
M
Hirashima
Naohide
N
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D001491:Basophils / Q000502:physiology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D005089:Exocytosis; D019204:GTP-Binding Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D051381:Rats
D048868:Adaptor Proteins, Signal Transducing; C479909:ERC1 protein, rat; D009419:Nerve Tissue Proteins; C491489:Rims1 protein, rat; C103912:Unc13a protein, rat; D019204:GTP-Binding Proteins