@article{d789eb610ae64aeba76d58fc8593cc51,
title = "Calmodulin directly interacts with the cx43 carboxyl-terminus and cytoplasmic loop containing three oddd-linked mutants (M147t, r148q, and t154a) that retain α-helical structure, but exhibit loss-of-function and cellular trafficking defects",
abstract = "The autosomal-dominant pleiotropic disorder called oculodentodigital dysplasia (ODDD) is caused by mutations in the gap junction protein Cx43. Of the 73 mutations identified to date, over one-third are localized in the cytoplasmic loop (Cx43CL) domain. Here, we determined the mechanism by which three ODDD mutations (M147T, R148Q, and T154A), all of which localize within the predicted 1-5-10 calmodulin-binding motif of the Cx43CL, manifest the disease. Nuclear magnetic resonance (NMR) and circular dichroism revealed that the three ODDD mutations had little-to-no effect on the ability of the Cx43CL to form α-helical structure as well as bind calmodulin. Combination of microscopy and a dye-transfer assay uncovered these mutations increased the intracellular level of Cx43 and those that trafficked to the plasma membrane did not form functional channels. NMR also identify that CaM can directly interact with the Cx43CT domain. The Cx43CT residues involved in the CaM interaction overlap with tyrosines phosphorylated by Pyk2 and Src. In vitro and in cyto data provide evidence that the importance of the CaM interaction with the Cx43CT may lie in restricting Pyk2 and Src phosphorylation, and their subsequent downstream effects.",
keywords = "Calmodulin, Circular dichroism, Connexin43, Cytoplasmic loop domain, Gap junctions, NMR, ODDD",
author = "Li Zheng and Sylvie Chenavas and Fabien Kieken and Andrew Trease and Sarah Brownell and Asokan Anbanandam and Sorgen, {Paul L.} and Gaelle Spagnol",
note = "Funding Information: This research was funded by grants from the National Institutes of Health (GM072631 and GM131092). Support for the UNMC Advanced Microscopy Core Facility was provided by the Nebraska Research Initiative and an Institutional Development Award (IDeA) from the NIGMS of the NIH (P30GM106397). The following NIH SIG funded instruments were used: LSM 800 Zeiss Confocal Microscope (NIH S10RR027301). The authors thank Ed Ezell for his assistance with NMR data collection, and Janice Taylor and James Talaska for their assistance with confocal microscopy imaging data collection. Funding Information: Funding: This research was funded by grants from the National Institutes of Health (GM072631 and GM131092). Support for the UNMC Advanced Microscopy Core Facility was provided by the Nebraska Research Initiative and an Institutional Development Award (IDeA) from the NIGMS of the NIH (P30GM106397). The following NIH SIG funded instruments were used: LSM 800 Zeiss Confocal Microscope (NIH S10RR027301). Publisher Copyright: {\textcopyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2020",
month = oct,
doi = "10.3390/biom10101452",
language = "English (US)",
volume = "10",
pages = "1--23",
journal = "Biomolecules",
issn = "2218-273X",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "10",
}