Mark/Par-1 marking the polarity of migrating neurons.

Proper brain development requires the orchestrated migration of neurons from their place of birth to their final positioning, where they will form appropriate connections with their target cells. These events require coordinated activity of multiple elements of the cytoskeleton, in which the MARK/Par-1 polarity kinase plays an important role. Here, the various roles and modes of regulation of MARK/Par-1 are reviewed. MARK/Par-1 participates in axon formation in primary hippocampal neurons. Balanced levels of MARK/Par-1 are required for proper radial migration, as well as for migration in the rostral migratory stream. Normal neuronal migration requires at least two of MARK/Par-1 substrates, DCX and tau. Overall, the positioning of MARK/Par-1 at the crosstalk of regulating cytoskeletal dynamics allows its participation in neuronal polarity decisions.