Endocytosis is the uptake of material into a cell in membrane-bound vesicles. The material is trafficked through different vesicles, depending on whether it will be degraded or recycled back to the surface of the cell. A recent paper identified a new player in this process called Ema, which is found on some late endosomal vesicles and plays a role in the maturation of these vesicles. Image shows Ema (green) and Rab5 (purple), an early endosomal protein.
Reference: Sungsu Kim, Yogesh P. Wairkar, Richard W. Daniels, and Aaron DiAntonio, 2010. Originally published in Journal of Cell Biology. doi: 10.1083/jcb.200911126. Paper can be found here.