It has previously been shown that growth factors that bind to transmembrane protein receptors can start signalling and induce their own internalization in cells. In the recent publication by Lauvrak et al. (Mol.Biol. Cell 17(2006) 1096-1109) the authors demonstrate that also a lipid-binding ligand can be responsible for signalling that mediates uptake. The finding reveals that there are still unexplored systems in the cell membrane that can influence the cells.
Growing cells have quality control of newly synthesized proteins - a process of importance for normal cell function. This control system ensures degradation of newly synthesized proteins that are misfolded, and might be utilized to bring external proteins into cells for therapeutic purposes. The research group has characterized how one individual member of this quality control system can mediate protein transport into the cell (Slominska-Wojewodska et al. Mol. Biol. Cell 17(2006) 1664-1675).