Alternative RNA splicing
Dr. Grabowski received her Ph.D. in 1983 with Tom Cech at the University of Colorado, performed her postdoctoral studies with Philip Sharp at the Massachusetts Institute of Technology, and joined the Department in 1991.
Alternative splicing and its regulation
Why do human cells express more protein varieties than the genes encoding them? How did this mismatch arise, and is it biologically purposeful? The upshot is that alternative pre-mRNA splicing pathways are responsible for producing molecular decisions in the form of messenger RNA transcripts, which diversify the forms and functions of protein families encoded in the genome. Ultimately, the spliceosome is the biochemical gatekeeper of splicing decisions. It must be nimble in the way it directs decisions about splice site recognition to favor or disfavor one splicing pathway over another, while preserving accuracy. Splicing decisions can have a profound impact on cellular fate and behavior. In the nervous system for example, the inhibition of certain splicing pathways relative to others can automate the time course of differentiation of neuronal precursors into mature cells, whereas other mechanisms specify connectivity patterns and electrical properties of neurons. In many cell types, splicing decisions can indeed have a beneficial effect on protein structure and function, while the elasticity of these pathways offers cells the means to adapt rapidly to local changes in the environment by coordinating their protein outputs.
The Grabowski lab is currently exploring how splicing pathways exhibit elasticity, which is seen by their responsiveness to environmental stimulation and stress. We have developed the Ca2+ permeable NMDA R1 receptor as a model system to understand the biochemistry underlying the elasticity of splicing in neurons, and we are extending our experiments to other model substrates in cancer cells. We are addressing the following set of questions using genetics, biochemistry, and genomics approaches.
Which key players in signaling pathways are activated to respond to environmental cues, and how is target specificity determined?
What is the
architecture of splicing codes at the level of pre-mRNA targets, and how do
these codes respond to the activated pathways?
How are splicing pathways reset after the external stimulus fades away, and what controls the kinetics of the reset mechanisms?
Dembowski JA, An P, Scoulos-Hansen M, Yeo G, Han J, Fu XD, and PJ Grabowski (2012) Alternative splicing of a novel inducible exon diversifies the CASK guanylate kinase domain. J. Nucleic Acids. 2012.2012:816237
Grabowski, P. (2011) Alternative splicing takes shape during development. Curr Opin Genet Dev. 21:388-94
Dembowski, J.A., and P.J. Grabowski (2009) The CUGBP2 splicing factor regulates an ensemble of branchpoints from perimeter binding sites with implications for autoregulation. PLoS Genet. 5:e1000595e1000
Grabowski, P.J. (2007) RNA-binding proteins switch gears to drive alternative splicing in neurons. Nat. Struct. Mol. Biol. 14:577-579
An, P., and P.J. Grabowski (2007) Exon silencing by UAGG motifs in response to neuronal excitation. PLoS Biol. 5:e36
Grabowski, P.J. (2005) Splicing-active nuclear extracts from rat brain. Methods 37:323-330
Xu, X.M., H. Mix, B.A. Carlson, P.J. Grabowski, V.N. Gladyshev, M.J. Berry, and D.L... Hatfield (2005) Evidence for direct roles of two additional factors, SECp43 and SLA, in the selenoprotein synthesis machinery. J. Biol. Chem. 280:568-575
Han, K., G. Yeo, P. An, C.B. Burge, and P.J. Grabowski (2005) A combinatorial code for splicing silencing: UAGG and GGGG motifs. PLoS Biol. 3:e158
Grabowski, P.J. (2004) A molecular code for splicing silencing: configurations of guanosine-rich motifs. Biochem. Soc. Trans. 32:924-927
Miné, M., M. Brivet, G. Touati, P. Grabowski, M. Abitbol, and C. Marsac (2003) Splicing error in E1alpha pyruvate dehydrogenase mRNA caused by novel intronic mutation responsible for lactic acidosis and mental retardation. J. Biol. Chem. 278:11768-11772
Black, D.L., and P.J. Grabowski (2003) Alternative pre-mRNA splicing and neuronal function. Prog. Mol. Subcell. Biol. 31:187-216
Grabowski, P. (2002) Alternative splicing in parallel. Nat. Biotechnol. 20:346-347
Zhang, W., H. Liu, K. Han, and P.J. Grabowski (2002) Region specific alternative splicing in the nervous system: implications for regulation by the RNA binding protein, NAPOR. RNA 8:671-685
Wu, J.I., R. Reed, P.J. Grabowski, and K. Artzt (2002) The function of quaking in myelination: Regulation of alternative splicing. Proc. Natl. Acad. Sci., USA 99:4233-4238
Liu, H., W. Zhang, R. Reed, W. Liu, and P.J. Grabowski (2002) Mutations in RRM4 uncouple the splicing repression and RNA-binding activities of polypyrimidine tract binding protein. RNA 8:137-149
Grabowski, P.J., and D.L. Black (2001) Alternative RNA splicing in the nervous system. Prog. Neurobiol. 65:289-308