EN
The precise control of the microtubule polymerization dynamics as well as strict actin organization are both crucial for formation of neuronal dendritic arbor and require microtubule and actin binding proteins activity. Cytoplasmic linker protein 170 (CLIP-170), one of microtubule plus-end binding proteins, regulates microtubule dynamics at plus-end during polymerization, by promoting rescuephase in its phosphorylation status dependent manner. We show evidence that mammalian target of rapamycin (mTOR), is one of kinases capable of regulating CLIP-170 activity and both, mTOR and CLIP-170 are crucial for proper dendritic arbor development of hippocampal neurons. Furthermore, we identifi ed in neurons several proteins, which bound to CLIP-170 when mTOR is active, including IQGAP1, a known partner of CLIP-170 and regulator of the actin dynamics. Taken together our data strongly suggest that CLIP-170 activity during dendritogenesis can be regulated by mTOR at the level of CLIP-170 protein-protein interactions. Moreover, obtained results, showing mTOR dependent interaction of CLIP-170 with IQGAP imply that mTOR can coordinate tubulin and actin cytoskeleton organization. Supported by Polish Ministry of Science and Higher Education Research Grant 2P04A01530 and Polish-Norwegian Research Found grant PNRF-96-AI-1/07.