Role of BMP receptor-associated molecule BRAM1 in BMP signaling

• Main Authors: Yu-Chen Hsu, 許瑜真
• Other Authors: Lian-Chen Wang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/07432403229453320294

碩士 === 長庚大學 === 基礎醫學研究所 === 92 === Bone morphogenetic protein induces signals through the stimulation of serine/threonine kinase receptors which phosphorylated BMP signaling mediators, Smad1, Smad5 and Smad4. The phosphorylated Smad1/5/4 complex is then translocated to the nucleus and regulates the BMP target genes. BMP receptor associated molecule 1 (BRAM1) is a molecule that associates with BMP receptor IA. However its role in BMP signaling is still unclear. Thus, the specific aims of this study are examined (1) if BRAM1 affects BMP signaling; (2) If so, are the Smad proteins classical BMP signaling mediators involved? In this study, we demonstrate that BRAM1 interacts with BMP receptor by co-immunoprecipitaion, Western blot and confocal microscopy. The results show that BRAM1 associates with wild type BMP receptor as well as the constitutively activated BMPR. The Mynd domain of BRAM1 is the main region for BRAM1-BMPR interaction. Confocal microscopy study showed that BRAM1 co-localized with BMPR and Smad5, but not with Smad1. Furthermore, BRAM1 prevents the nucleus translocation of Smad4 in response to BMP treatment. Thus the results suggest that BRAM1 may be involved in BMP signaling. This study will provide more information regarding the function of BRAM1.