Sertad1 encodes a novel transcriptional co-activator of SMAD1 in mouse embryonic hearts

• Published in: Biochemical and biophysical research communications 2013-11, Vol.441 (4), p.751-756
• Main Authors: Peng, Yin, Zhao, Shaomin, Song, Langying, Wang, Manyuan, Jiao, Kai
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; BIOLOGICAL REPAIR; BMP signaling; Bone Morphogenetic Proteins - metabolism; Cardiogenesis; cardiomyocytes; CARDIOVASCULAR DISEASES; Cell Nucleus - metabolism; CYTOPLASM; Cytoplasm - metabolism; DISEASE INCIDENCE; dose response; Gene Expression Regulation, Developmental; GENES; HEART; Heart - embryology; heart diseases; HYBRIDIZATION; IN VITRO; IN-SITU HYBRIDIZATION; INFANTS; MICE; morbidity; MORTALITY; Myocytes, Cardiac - metabolism; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Organogenesis - genetics; POLYMERASE CHAIN REACTION; reverse transcriptase polymerase chain reaction; SMAD1; Smad1 Protein - genetics; Smad1 Protein - metabolism; SURGERY; Trans-Activators - genetics; Trans-Activators - metabolism; transcription (genetics); Transcription, Genetic; Transcriptional Activation; Transcriptional co-activator; two hybrid system techniques; Western blotting; Yeast two-hybrid; YEASTS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2013.10.127

•SERTAD1 interacts with SMAD1.•Sertad1 is expressed in mouse embryonic hearts.•SERTAD1 is localized in both cytoplasm and nucleus of cardiomyocytes.•SERTAD1 enhances expression of BMP target cardiogenic genes as a SMAD1 co-activator. Despite considerable advances in surgical repairing procedures, congenital heart diseases (CHDs) remain the leading noninfectious cause of infant morbidity and mortality. Understanding the molecular/genetic mechanisms underlying normal cardiogenesis will provide essential information for the development of novel diagnostic and therapeutic strategies against CHDs. BMP signaling plays complex roles in multiple cardiogenic processes in mammals. SMAD1 is a canonical nuclear mediator of BMP signaling, the activity of which is critically regulated through its interaction partners. We screened a mouse embryonic heart yeast two-hybrid library using Smad1 as bait and identified SERTAD1 as a novel interaction partner of SMAD1. SERTAD1 contains multiple potential functional domains, including two partially overlapping transactivation domains at the C terminus. The SERTAD1-SMAD1 interaction in vitro and in mammalian cells was further confirmed through biochemical assays. The expression of Sertad1 in developing hearts was demonstrated using RT-PCR, western blotting and in situ hybridization analyses. We also showed that SERTAD1 was localized in both the cytoplasm and nucleus of immortalized cardiomyocytes and primary embryonic cardiomyocyte cultures. The overexpression of SERTAD1 in cardiomyocytes not only enhanced the activity of two BMP reporters in a dose-dependent manner but also increased the expression of several known BMP/SMAD regulatory targets. Therefore, these data suggest that SERTAD1 acts as a SMAD1 transcriptional co-activator to promote the expression of BMP target genes during mouse cardiogenesis.