| Structural highlights
Function
[CAC1A_DROME] Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, neurotransmitter release, gene expression, cell motility, cell division and cell death (By similarity). Probably encodes a dihydropyridine-insensitive current. Vital for survival to adulthood.[1] [2]
Publication Abstract from PubMed
Synaptic vesicles (SVs) fuse at active zones (AZs) covered by a protein scaffold, at Drosophila synapses comprised of ELKS family member Bruchpilot (BRP) and RIM-binding protein (RBP). We here demonstrate axonal co-transport of BRP and RBP using intravital live imaging, with both proteins co-accumulating in axonal aggregates of several transport mutants. RBP, via its C-terminal Src-homology 3 (SH3) domains, binds Aplip1/JIP1, a transport adaptor involved in kinesin-dependent SV transport. We show in atomic detail that RBP C-terminal SH3 domains bind a proline-rich (PxxP) motif of Aplip1/JIP1 with submicromolar affinity. Pointmutating this PxxP motif provoked formation of ectopic AZ-like structures at axonal membranes. Direct interactions between AZ proteins and transport adaptors seem to provide complex avidity and shield synaptic interaction surfaces of pre-assembled scaffold protein transport complexes, thus, favouring physiological synaptic AZ assembly over premature assembly at axonal membranes.
A high affinity RIM-binding protein/Aplip1 interaction prevents the formation of ectopic axonal active zones.,Siebert M, Bohme MA, Driller JH, Babikir H, Mampell MM, Rey U, Ramesh N, Matkovic T, Holton N, Reddy-Alla S, Gottfert F, Kamin D, Quentin C, Klinedinst S, Andlauer TF, Hell SW, Collins CA, Wahl MC, Loll B, Sigrist SJ Elife. 2015 Aug 14;4. doi: 10.7554/eLife.06935. PMID:26274777[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Smith LA, Wang X, Peixoto AA, Neumann EK, Hall LM, Hall JC. A Drosophila calcium channel alpha1 subunit gene maps to a genetic locus associated with behavioral and visual defects. J Neurosci. 1996 Dec 15;16(24):7868-79. PMID:8987815
- ↑ Smith LA, Peixoto AA, Kramer EM, Villella A, Hall JC. Courtship and visual defects of cacophony mutants reveal functional complexity of a calcium-channel alpha1 subunit in Drosophila. Genetics. 1998 Jul;149(3):1407-26. PMID:9649530
- ↑ Siebert M, Bohme MA, Driller JH, Babikir H, Mampell MM, Rey U, Ramesh N, Matkovic T, Holton N, Reddy-Alla S, Gottfert F, Kamin D, Quentin C, Klinedinst S, Andlauer TF, Hell SW, Collins CA, Wahl MC, Loll B, Sigrist SJ. A high affinity RIM-binding protein/Aplip1 interaction prevents the formation of ectopic axonal active zones. Elife. 2015 Aug 14;4. doi: 10.7554/eLife.06935. PMID:26274777 doi:http://dx.doi.org/10.7554/eLife.06935
|
