Cloning and Expression of Neurotrophic Trypanosoma cruzi Ribosomal Proteins.
- Trypanosoma cruzi, the infectious agent of Chagas' Disease, has a mimic of nerve growth factor (NGF), known as parasite-derived neurotrophic factor (PDNF). PDNF binds to the NGF receptor TrkA and promotes the survival and differentiation of neuronal cells, as well as entry into the cell by T. cruzi. A screen for T. cruzi proteins that mimic other neurotrophic factors was performed, and a T. cruzi ... read moremimic of glial cell-derived neurotrophic factor (GDNF) was identified by its binding to the GDNF family of ligands (GFL) receptors GFRalpha-1, 2, and 3. GDNF, like NGF, is a neurotrophic factor involved in neural cell growth and survival. TGFL, like the ligands it imitates, appears to promote cell survival and neurite outgrowth. It is a complex of proteins expressed on the surface of T. cruzi. Sequencing analyses revealed many of the proteins in TGFL to be T. cruzi ribosomal proteins, including ribosomal proteins L13 and L4. In order to better understand the role of TGFL in T. cruzi infection, L13 and L4 were cloned and bacterially expressed. Although attempts at purification were met with some difficulties, the cloned genes will allow for the eventual purification of the recombinant ribosomal proteins, and elucidation of their role in infection. Once purified, we will test their biological activity, specifically whether these ribosomal proteins can bind GFRalpha-1,2, or 3 individually, and whether they are capable of promoting neuronal survival and differentiation like TGFL.read less