Nucleocytoplasmic shuttling of the Duchenne muscular dystrophy gene product dystrophin Dp71d is dependent on the importin a/b and CRM1 nuclear transporters and microtubule motor dynein

R Suarz-Sanchez, A Aguilar, Kylie Michelle Wagstaff, G Velez, P M Azuara-Medina, P Gomez, A Vasquez-Limeta, O Hernandez-Hernandez, Kim Gia Lieu, David Andrew Jans, Bulmaro Cisneros

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

Even though the Duchenne muscular dystrophy (DMD) gene product Dystrophin Dp71d is involved in various key cellular processes through its role as a scaffold for structural and signalling proteins at the plasma membrane as well as the nuclear envelope, its subcellular trafficking is poorly understood. Here we map the nuclear import and export signals of Dp71d by truncation and point mutant analysis, showing for the first time that Dp71d shuttles between the nucleus and cytoplasm mediated by the conventional nuclear transporters, importin (IMP) alpha/beta and the exportin CRM1. Binding was confirmed in cells using pull-downs, while in vitro binding assays showed direct, high affinity (apparent dissociation coefficient of c. 0.25nM) binding of Dp71d to IMPalpha/beta. Interestingly, treatment of cells with the microtubule depolymerizing reagent nocodazole or the dynein inhibitor EHNA both decreased Dp71d nuclear localization, implying that Dp71d nuclear import may be facilitated by microtubules and the motor protein dynein. The role of Dp71d in the nucleus appears to relate in part to interaction with the nuclear envelope protein emerin, and maintenance of the integrity of the nuclear architecture. The clear implication is that Dp71d s previously unrecognised nuclear transport properties likely contribute to various, important physiological roles.
Original languageEnglish
Pages (from-to)985 - 1001
Number of pages17
JournalBiochimica et Biophysica Acta - Molecular Cell Research
Volume1843
Issue number5
DOIs
Publication statusPublished - 2014

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