Published online 8 January 2006
Article |
Oct-2 DNA binding transcription factor: functional consequences of phosphorylation and glycosylation
1Institute of Molecular Sciences and Bioinformatics Lahore, Pakistan 2Department of Pathology and Immunology, Centre Médical Universitaire Geneva, Switzerland 3School of Biological Sciences, University of the Punjab Lahore, Pakistan 4HEJ Research Institute of Chemistry, University of Karachi Karachi, Pakistan
*To whom correspondence should be addressed. Tel: +92 42 8435838; Fax: +92 42 731 2197; Email: nasir{at}super.net.pk
Received October 13, 2005. Revised December 1, 2005. Accepted December 1, 2005.
Phosphorylation and O-GlcNAc modification often induce conformational changes and allow the protein to specifically interact with other proteins. Interplay of phosphorylation and O-GlcNAc modification at the same conserved site may result in the protein undergoing functional switches. We describe that at conserved Ser/Thr residues of human Oct-2, alternative phosphorylation and O-GlcNAc modification (Yin Yang sites) can be predicted by the YinOYang1.2 method. We propose here that alternative phosphorylation and O-GlcNAc modification at Ser191 in the N-terminal region, Ser271 and 274 in the linker region of two POU sub-domains and Thr301 and Ser323 in the POUh subdomain are involved in the differential binding behavior of Oct-2 to the octamer DNA motif. This implies that phosphorylation or O-GlcNAc modification of the same amino acid may result in a different binding capacity of the modified protein. In the C-terminal domain, Ser371, 389 and 394 are additional Yin Yang sites that could be involved in the modulation of Oct-2 binding properties.