RESUMEN
TBX5 is a T-box family transcription factor that regulates heart and forelimb development in vertebrates and functional deficiencies in this protein result in Holt-Oram syndrome. Recently, we have shown that acetylation of TBX5 potentiates its activity and is important for heart and limb development. Here we report that class II histone deacetylases HDAC4 and HDAC5 associate with TBX5 and repress its role in cardiac gene transcription. Both HDAC4 and HDAC5 deacetylate TBX5, which promotes its relocation to the cytoplasm and HDAC4 antagonizes the physical association and functional cooperation between TBX5 and MEF2C. We also show that protein kinase D1 (PRKD1) relieves the HDAC4/5-mediated repression of TBX5. Thus, this study reveals a novel interaction of HDAC4/5 and PRKD1 in the regulation of TBX5 transcriptional activity.
Asunto(s)
Histona Desacetilasas/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Represoras/metabolismo , Proteínas de Dominio T Box/metabolismo , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Acetilación , Animales , Células COS , Chlorocebus aethiops , Clonación Molecular , Citoplasma/metabolismo , Cardiopatías Congénitas/genética , Cardiopatías Congénitas/patología , Defectos del Tabique Interatrial/genética , Defectos del Tabique Interatrial/patología , Deformidades Congénitas de las Extremidades Inferiores/genética , Deformidades Congénitas de las Extremidades Inferiores/patología , Factores de Transcripción MEF2/metabolismo , Proteína Quinasa C/genética , Proteína Quinasa C/aislamiento & purificación , Ratas , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Proteínas de Dominio T Box/genética , Transcripción Genética , Transfección , Deformidades Congénitas de las Extremidades Superiores/genética , Deformidades Congénitas de las Extremidades Superiores/patologíaRESUMEN
TBX5 plays a critical role in heart and forelimb development. Mutations in TBX5 cause Holt-Oram syndrome, an autosomal dominant condition that affects the formation of the heart and upper-limb. Several studies have provided significant insight into the role of TBX5 in cardiogenesis; however, how TBX5 activity is regulated by other factors is still unknown. Here we report that histone acetyltransferases KAT2A and KAT2B associate with TBX5 and acetylate it at Lys339. Acetylation potentiates its transcriptional activity and is required for nuclear retention. Morpholino-mediated knockdown of kat2a and kat2b transcripts in zebrafish severely perturb heart and limb development, mirroring the tbx5a knockdown phenotype. The phenotypes found in MO-injected embryos were also observed when we introduced mutations in the kat2a or kat2b genes using the CRISPR-Cas system. These studies highlight the importance of KAT2A and KAT2B modulation of TBX5 and their impact on heart and limb development.
