The Bone Morphogenetic Protein (BMP) Signaling Pathway is evolutionarily conserved with significant roles in regulations of multiple developmental processes. Its regulation is achieved by modulation of the BMP ligand availability and the receptor relay molecules activities targeting downstream gene regulation. This conserved BMP signaling pathway, a.k.a., the Sma/Mab pathway in C. elegans, plays a significant role in the body length regulation. To understand the extracellular regulation of the Sma/Mab signaling, this study focused on sma-10, a gene encoding a leucine-rich repeats and immunoglobulin-like domains protein that enhances the Sma/Mab signal. My work aimed to understand expression profile of sma-10, to identify the required protein domains of SMA-10 for Sma/Mab signali...[ Read more ]

The Bone Morphogenetic Protein (BMP) Signaling Pathway is evolutionarily conserved with significant roles in regulations of multiple developmental processes. Its regulation is achieved by modulation of the BMP ligand availability and the receptor relay molecules activities targeting downstream gene regulation. This conserved BMP signaling pathway, a.k.a., the Sma/Mab pathway in C. elegans, plays a significant role in the body length regulation. To understand the extracellular regulation of the Sma/Mab signaling, this study focused on sma-10, a gene encoding a leucine-rich repeats and immunoglobulin-like domains protein that enhances the Sma/Mab signal. My work aimed to understand expression profile of sma-10, to identify the required protein domains of SMA-10 for Sma/Mab signaling modulation and to elucidate the impact of SMA-10 on SMA-6/DAF-4 receptor complex trafficking. We revealed that sma-10 is constitutively expressed in the pharynx, intestine and hypodermis at steady levels throughout the larval development. All the extracellular domains of SMA-10 are required while membrane anchorage is dispensable for its functionality. We have further identified large SMA-6 containing intracellular vesicles in the intestinal cells of sma-10 mutant, suggesting a potential linkage between the Sma/Mab regulation and the intracellular trafficking of Type I BMP receptor regulated by SMA-10.