Evolutionary conservation of complexins: from choanoflagellates to mice.
Complexins are synaptic SNARE complex-binding proteins that cooperate with synaptotagmins in activating Ca(2+)-stimulated, synaptotagmin-dependent synaptic vesicle exocytosis and in clamping spontaneous, synaptotagmin-independent synaptic vesicle exocytosis. Here, we show that complexin sequences are conserved in some non-metazoan unicellular organisms and in all metazoans, suggesting that complexins are a universal feature of metazoans that predate metazoan evolution. We show that complexin from Nematostella vectensis, a cnidarian sea anemone far separated from mammals in metazoan evolution, functionally replaces mouse complexins in activating Ca(2+)-triggered exocytosis, but is unable to clamp spontaneous exocytosis. Thus, the activating function of complexins is likely conserved throughout metazoan evolution.
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute Stanford University School of Medicine, Stanford, CA, USA College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, China sunlittlefly@hotmail.com tcs1@stanford.edu.
Xiaofei
X
Yang
Department of Biophysics, Howard Hughes Medical Institute University of Texas Southwestern Medical Center, Dallas, TX, USA.
Jimin
J
Pei
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute Stanford University School of Medicine, Stanford, CA, USA.
Yea Jin
YJ
Kaeser-Woo
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute Stanford University School of Medicine, Stanford, CA, USA.
Taulant
T
Bacaj
Department of Biophysics, Howard Hughes Medical Institute University of Texas Southwestern Medical Center, Dallas, TX, USA.
Nick V
NV
Grishin
Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute Stanford University School of Medicine, Stanford, CA, USA sunlittlefly@hotmail.com tcs1@stanford.edu.
Thomas C
TC
Südhof
D033942:Adaptor Proteins, Vesicular Transport / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D002118:Calcium / Q000378:metabolism; D056897:Choanoflagellata / Q000737:chemistry / Q000235:genetics*; D017124:Conserved Sequence; D005089:Exocytosis; D051379:Mice; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding / Q000235:genetics*; D017433:Protein Structure, Secondary; D050600:SNARE Proteins; D009435:Synaptic Transmission; D050857:Synaptotagmins / Q000235:genetics / Q000502:physiology
D033942:Adaptor Proteins, Vesicular Transport; D009419:Nerve Tissue Proteins; D050600:SNARE Proteins; D050857:Synaptotagmins; D002118:Calcium
SNARE proteins; evolution; membrane fusion; synapse; synaptotagmin