Interaction of Pax6 with SPARC and p53 in brain of mice indicates Smad3 dependent auto-regulation.

Pax6 regulates formation of cerebral cortex, axon guidance, differentiation of neurons from glia and neuronal migration in the cerebellum. Although Pax6 is known to be a nuclear protein, it is presumed that it may interact with matricelluar proteins like SPARC during transport and processing of Pax6. The proteins involved in cell survival and cell proliferation can also not be ignored. The present study demonstrates co-localization of Pax6, secreted protein acidic rich in cysteine (SPARC), and p53 in astrocytes of primary culture, cerebellum and cortex region of mouse brain. The physical interaction of Pax6 with SPARC and p53 in brain of mice is also evident. The Pax6 probably participates with p53 to regulate neuronal survival. It indicates that the interaction of Pax6, SPARC and p53 may influence Smad3-dependent auto-regulation of Pax6.