New findings important for understanding endosome function published in Cell
The Stenmark group tries to understand how cell signalling is modulated by internalization of growth factor receptors. Internalization of such receptors is followed by their transfer to specialized organelles called endosomes. From here, the receptors may be recycled back to the cell surface or transported to lysosomes for degradation.
Alicia Cabezas from Stenmark's group is one of the co-authors on this important paper published in Cell (click to enlarge image)
The Stenmark group has previously established that a specialized lipid, PI3P, is crucial for endocytic membrane trafficking, and a collaborating group, that of Marino Zerial at the Max Planck Institute for Molecular Biology and Genetics in Dresden, has found that PI3P is required for the bidirectional movement of endosomes along microtubules. While such movement can be easily visualed by live-cell microscopy, its importance for receptor trafficking and signalling has not been known, nor has its molecular basis been understood.
Now, through an EU-sponsored collaboration, the Stenmark and Zerial groups have identified a motor protein called KIF16B, which binds PI3P on the surface of endosomes and moves them in the + direction along microtubules, to the cell periphery. This facilitates receptor recycling and inhibits receptor degradation.
The new findings are important for understanding the function of endosomes in receptor trafficking and signalling and has been published in the May 6th issue of Cell! (Impact factor: 26.6). The title of the article is "Modulation of Receptor Recycling and Degradation by the Endosomal Kinesin KIF16B".