28.04.2018

Restoring functional neurofibromin by protein transduction - new publication

New article in Nature Scientific Reports by team members of University of Ulm and Biocenter, Innsbruck Medical University, Austria, in cooperation with Kemkemer group.

More information at https://www.nature.com/articles/s41598-018-24310-5 

K. Mellert, S. Lechner, M. Lüdeke, M. Lamla, P. Möller, R. Kemkemer, K. Scheffzek &  D. Kaufmann

Restoring functional neurofibromin by protein transduction

Abstract

In Neurofibromatosis 1 (NF1) germ line loss of function mutations result in reduction of cellular neurofibromin content (NF1+/−, NF1haploinsufficiency). The Ras-GAP neurofibromin is a very large cytoplasmic protein (2818 AA, 319 kDa) involved in the RAS-MAPK pathway. Aside from regulation of proliferation, it is involved in mechanosensoric of cells. We investigated neurofibromin replacement in cultured human fibroblasts showing reduced amount of neurofibromin. Full length neurofibromin was produced recombinantly in insect cells and purified. Protein transduction into cultured fibroblasts was performed employing cell penetrating peptides along with photochemical internalization. This combination of transduction strategies ensures the intracellular uptake and the translocation to the cytoplasm of neurofibromin. The transduced neurofibromin is functional, indicated by functional rescue of reduced mechanosensoric blindness and reduced RasGAP activity in cultured fibroblasts of NF1 patients or normal fibroblasts treated by NF1 siRNA. Our study shows that recombinant neurofibromin is able to revert cellular effects of NF1-haploinsuffiency in vitro, indicating a use of protein transduction into cells as a potential treatment strategy for the monogenic disease NF1.