| First Author | Xue R | Year | 2015 |
| Journal | Proc Natl Acad Sci U S A | Volume | 112 |
| Issue | 31 | Pages | E4316-25 |
| PubMed ID | 26195798 | Mgi Jnum | J:226054 |
| Mgi Id | MGI:5695709 | Doi | 10.1073/pnas.1502288112 |
| Citation | Xue R, et al. (2015) Structural elements that underlie Doc2beta function during asynchronous synaptic transmission. Proc Natl Acad Sci U S A 112(31):E4316-25 |
| abstractText | Double C2-like domain-containing proteins alpha and beta (Doc2alpha and Doc2beta) are tandem C2-domain proteins proposed to function as Ca(2+) sensors for asynchronous neurotransmitter release. Here, we systematically analyze each of the negatively charged residues that mediate binding of Ca(2+) to the beta isoform. The Ca(2+) ligands in the C2A domain were dispensable for Ca(2+)-dependent translocation to the plasma membrane, with one exception: neutralization of D220 resulted in constitutive translocation. In contrast, three of the five Ca(2+) ligands in the C2B domain are required for translocation. Importantly, translocation was correlated with the ability of the mutants to enhance asynchronous release when overexpressed in neurons. Finally, replacement of specific Ca(2+)/lipid-binding loops of synaptotagmin 1, a Ca(2+) sensor for synchronous release, with corresponding loops from Doc2beta, resulted in chimeras that yielded slower kinetics in vitro and slower excitatory postsynaptic current decays in neurons. Together, these data reveal the key determinants of Doc2beta that underlie its function during the slow phase of synaptic transmission. |
