Calsyntenin-1 docks vesicular cargo to kinesin-1.
We identified a direct interaction between the neuronal transmembrane protein calsyntenin-1 and the light chain of Kinesin-1 (KLC1). GST pulldowns demonstrated that two highly conserved segments in the cytoplasmic domain of calsyntenin-1 mediate binding to the tetratricopeptide repeats of KLC1. A complex containing calsyntenin-1 and the Kinesin-1 motor was isolated from developing mouse brain and immunoelectron microscopy located calsyntenin-1 in association with tubulovesicular organelles in axonal fiber tracts. In primary neuronal cultures, calsyntenin-1-containing organelles were aligned along microtubules and partially colocalized with Kinesin-1. Using live imaging, we showed that these organelles are transported along axons with a velocity and processivity typical for fast axonal transport. Point mutations in the two kinesin-binding segments of calsyntenin-1 significantly reduced binding to KLC1 in vitro, and vesicles bearing mutated calsyntenin-1 exhibited a markedly altered anterograde axonal transport. In summary, our results indicate that calsyntenin-1 links a certain type of vesicular and tubulovesicular organelles to the Kinesin-1 motor.
Konecna
Anetta
A
Department of Biochemistry and Brain Research Institute, University of Zurich, CH-8057 Zürich, Switzerland.
Frischknecht
Renato
R
Kinter
Jochen
J
Ludwig
Alexander
A
Steuble
Martin
M
Meskenaite
Virginia
V
Indermühle
Martin
M
Engel
Marianne
M
Cen
Chuan
C
Mateos
José-Maria
JM
Streit
Peter
P
Sonderegger
Peter
P
D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D017124:Conserved Sequence; D022162:Cytoplasmic Vesicles / Q000378:metabolism*; D020439:Growth Cones / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley
D002135:Calcium-Binding Proteins; C503227:Clstn1 protein, mouse; C513820:Clstn1 protein, rat; C000715688:KLC1 protein, human; C000715690:Klc1 protein, rat; C000715695:Kns2 protein, mouse; D008869:Microtubule-Associated Proteins; D016547:Kinesins