PKM and osteosarcoma: In order to check whether the ubiquitination of PKM2 by the laforin/malin complex could affect its translocation to the nucleus, we transfected human osteosarcoma U2OS cells [which are larger than HEK293 cells, so the different subcellular compartments (especially nucleus) are better observed] with myc-PKM2 in the presence or absence of FLAG-laforin and HA-malin.