Page 36 - IBRO_RNA School_Abstract Book

Non-coding RNAs: novel transport route and function in
developing axons

Marie Laure Baudet

University of Trento, Italy

During development, axons navigate a complex environment before reaching
their final destination. The distance created between the axonal leading tip, the
growth cone, and the cell body poses a particular challenge to developing
neurons. Indeed, growth cones must be able to rapidly and accurately
transduce environmental information to ensure highly precise directional
steering, without the immediate intervention from the soma. To overcome this

challenge, growth cones can store but also locally produce and fine-tune the
levels of their own proteins through local protein synthesis (LPS), from a rich
repertoire of mRNAs that is selectively trafficked there. Recent evidence
suggests that not only mRNAs but non-coding RNAs (ncRNAs) including
specific miRNAs are delocalized to and enriched within axons. The
mechanisms of ncRNA transport to these compartments and the biological
functions of local ncRNAs have, however, remained elusive. We will present
evidence suggesting that miRNAs are trans-located to the growth cone by
hitchhiking to endosomes and constitute a critical component of an RNA-based
signaling pathway that locally regulates LPS to elicit directional steering.