Open AccessLeucine‐rich repeat containing protein LRRC8A is essential for swelling‐activated Cl − currents and embryonic development in zebrafish
Author(s) -
Yamada Toshiki,
Wondergem Robert,
Morrison Rebecca,
Yin Viravuth P.,
Strange Kevin
Publication year - 2016
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12940
Subject(s) - zebrafish , gene knockdown , morpholino , biology , microbiology and biotechnology , embryogenesis , gene , leucine rich repeat , embryo , genetics
A volume‐regulated anion channel ( VRAC ) has been electrophysiologically characterized in innumerable mammalian cell types. VRAC is activated by cell swelling and mediates the volume regulatory efflux of Cl − and small organic solutes from cells. Two groups recently identified the mammalian leucine‐rich repeat containing protein LRRC 8A as an essential VRAC component. LRRC 8A must be coexpressed with at least one of the other four members of this gene family, LRRC 8B‐E , to reconstitute VRAC activity in LRRC 8 −/− cells. LRRC 8 genes likely arose with the origin of chordates. We identified LRRC 8A and LRRC 8C‐E orthologs in the zebrafish genome and demonstrate that zebrafish embryo cells and differentiated adult cell types express a swelling‐activated Cl − current indistinguishable from mammalian VRAC currents. Embryo cell VRAC currents are virtually eliminated by morpholino knockdown of the zebrafish LRRC 8A ortholog lrrc8aa . VRAC activity is fully reconstituted in LRRC 8 −/− human cells by coexpression of zebrafish lrrc8aa and human LRRC 8C cDNA s. lrrc8aa expression varies during zebrafish embryogenesis and lrrc8aa knockdown causes pericardial edema and defects in trunk elongation and somatogenesis. Our studies provide confirmation of the importance of LRRC 8A in VRAC activity and establish the zebrafish as a model system for characterizing the molecular regulation and physiological roles of VRAC and LRRC 8 proteins.