Abstract
Abstract: :
Purpose: To characterise the function of the RPGR protein, which is mutated in X-linked retinitis pigmentosa, by searching for interacting proteins. Methods: Protein pull-downs were carried out using immobilised bovine RPGR ORF15 C terminal fragment (C2) and bovine retinal extracts. Bound proteins were fractionated by SDS-PAGE, gel bands excised, digested in situ with trypsin and identified by peptide mass mapping using MALDI-TOF mass spectrometry. Yeast two-hybrid analyses were used to test whether the interaction is direct or indirect. COS cell transfections were carried out and co-localisation investigated using antibodies to an epitope tag fused to the C2 fragment and to the 40 kDa protein. Results: A 40 kDa centrosome-associated protein was identified as a new potential RPGR ORF15 (C2) interacting protein by protein pull-down and peptide mass fingerprinting from bovine retinal extracts. Initial yeast two-hybrid results suggest a direct but weak interaction with RPGR. COS cell transfection of RPGR ORF15 C2 showed co-localisation with the cognate 40 kDa protein using specific antibodies. Conclusion: A 40 kDa centrosome-associated protein shows evidence of specific interaction with the RPGR ORF15 C terminal fragment.
Keywords: 562 retinal degenerations: hereditary • 555 retina: distal(photoreceptors, horizontal cells, bipolar cells) • 526 protein purification and characterization