[The function of 5'flanking region of mouse neuronal CDC2-like kinase regulatory subunit p35].

OBJECTIVE

To clarify the possible mechanisms which control p35(nck5a) neural-specific expression.

METHODS

Thirteen luciferase expression vectors which contain different parts of 5'flanking sequence were constructed. Transient expression assay, DNase 1 hypersensitive site(DHSS) assay and primer extension assay were made to reveal the possible mechanisms of p35(nck5a) expression control.

RESULTS

It was found that 5'flanking sequence of p35(nck5a) contained 5455bp and there were a few possible promoters in the fragment. The result of transient expression assay in primary cerebrum cortex cell of rat (Neuron) and established non-neuron cell such as HeLa showed the loss of neural-specific expression of all the luciferase expression vectors. The result of DNase 1 hypersensitive site assay revealed a DHSS located at the -400bp upstream of p35(nck5a) in brain but not in liver. The primer extension assay found the putative transcription initiation site near the position of DHSS.

CONCLUSION

The results above suggest that there is no cis-element to control the neural-specific expression in the 5'flanking sequence, and the control on the chromosome level may be critical to the neural-specific expression of p35(nck5a).