Receptor-'Ck' dependent signalling regulates the LDL-receptor gene transcription.

Evidence of a novel receptor, having affinity for cholesterol in lipoproteins and intrinsic tyrosine kinase activity (designated as Receptor 'Ck') prompted us to explore its role in LDL-dependent transcriptional regulation of apoprotein-B specific LDL receptor gene in human lymphocytes. The results of this study revealed that LDL dependent activation of this Receptor 'Ck' was essential for the regulation of apoprotein-B specific LDL receptor gene transcription. Further, by using various blockers of as well as simulating the Receptor 'Ck'-dependent signalling in human lymphocytes, we were able to show that Receptor 'Ck'-dependent signalling was involved in the LDL-dependent transcriptional regulation of 160 kDa apoprotein B specific LDL receptor gene. Based upon these results, we conclude that cholesterol derived from LDL. catabolism within the cell does not have any role in the transcriptional regulation of apoprotein B specific LDL receptor gene.