I have been working towards understanding the molecular features of SR protein kinase 1 using x-ray crystallography. I investigated several crystal structures; apo-SRPK1 and SRPK1/ADP binary complex and SRPK1/ADP/peptide ternary complex. In addition to crystallography, I performed extensive mutagenesis and functional analysis of SRPK1. My structure has led to the discovery of how SRPK and Clk/Sty, a splicing kinase in the nucleus, coordinate in regulating subcellular and subnuclear localization of SR proteins. One manuscript made the cover of the October 7, 2005 issue of Molecular Cell! (see note below on Ngo et al., 2005). Using crystals of SRPK1 bound to full length ASF/SF2, my final project was identify conditions to obtain large diffracting crystals and determine the molecular structure of the complex. This will be the first structure of kinase bound to a native substrate.

PUBLICATIONS (resulting from this training)

Nolen B, Ngo J, Chakrabarti S, Vu D, Adams JA, Ghosh G. (2003) Nucleotide-induced conformational changes in the Saccharomyces cerevisiae SR protein kinase, Sky1p, revealed by X-ray crystallography. Biochemistry 42:9575-85.

Aubol BE, Chakrabarti S, Ngo J, Shaffer J, Nolen B, Fu XD, Ghosh G, Adams JA. (2003) Processive phosphorylation of alternative splicing factor/splicing factor 2. Proc Natl Acad Sci USA 100:12601-6.

Ngo JC, Chakrabarti S, Ding JH, Velazquez-Dones A, Nolen B, Aubol BE, Adams JA, Fu XD, Ghosh G. (2005) Interplay between SRPK and Clk/Sty kinases in phosphorylation of the splicing factor ASF/SF2 is regulated by a docking motif in ASF/SF2. Mol Cell 20:77-89. NOTE: This article was chosen for the cover of Molecular Cell. To see the cover caption and complete article, click here.

Ngo JC, Gullingsrud J, Giang K, Yeh MJ, Fu XD, Adams JA, McCammon JA, Ghosh G. (2007) SR Protein Kinase 1 Is Resilient to Inactivation. Structure. 15:123-33.

Ngo, J.C.K., Giang, K., Chakrabarti, S., Fu, X-D., Adams, J.A., and Ghosh, G. (2007) Crystal structure of SRPK1:ASF/SF2 complex: insights into regulation of SR protein. In Preparation.