Kinesins in MAPK cascade: How kinesin motors are involved in the MAPK pathway?

Kinesins are essential for the transport and positioning of several biomolecules through moving along the microtubule in eukaryotic cells. Up to now, there are 14 kinesin family proteins known. The MAPK pathway which is composed of multiple proteins constituting a complex cascade also plays important roles in cell proliferation, differentiation and apoptosis in eukaryotic cells. MAPK pathway includes three main kinases: MAPK Kinase Kinase, MAPK Kinase and mitogen-activated protein kinase that activate and phosphorylate downstream step by step in which abundant proteins scaffold together in complex ways. To accomplish the transmission of a variety of signals, numbers of kinesins are closely associated with the MAPK cascade such as Kinesin-1, Kinesin-3, Kinesin-5, Kinesin-8, Kinesin-11 and Kinesin-13 families in mammals and two kinds of kinesin-like proteins in plants. Studies have indicated that Kinesin-1 light chain KLC1, Kinesin-1 heavy chain KIF5B and Kinesin-11 family motor KIF26B interact with extracellular signal-regulated kinase ERK closely to regulate neuronal differentiation and mediate the chemosensitivity of osteosarcoma cells to drugs, Kinesin-3 family motor KIF13B and Kinesin-5 family motor Eg5 perform functions in regulating p38 to regulate the myelination of nervous system and facilitate the spindle elongation and tension, Kinesin-8 family motor MS-KIF18A and three isoforms of kinesin-13 can also connect and interact with MAPK pathway to transport estrogen receptor to the nucleus and control cell migration. In plant cells, NPK1-activating kinesin-like protein 1 NACK and AtNACK1 (HIK) kinesin-like protein HINKEL are two members of the plant-specific kinesin-7. They function as Ras at the upstream of MAPK pathway to regulate cytokinesis. This review summarizes the novel roles of kinesins in MAPK cascade and tries to discuss the mechanism of the interaction between them using mammalian and plant cells as models.