Many eukaryotic protein-encoding genes are interrupted by intervening sequences (IVSs) which are excised from mRNA precursors (pre-mRNAs) by RNA splicing. The long-term objective of the Investigator's research is to understand how pre-mRNA splice sites are correctly recognized and joined in an orderly way during RNA splicing. In previous work, Dr. Spritz has studied the sequence requirements for splice site recognition, the pathways by which IVSs are excised from complex pre-mRNAs, alternative pre-mRNA splicing, sites by and the structure of U1 small nuclear ribonucleoprotein complexes (snRNP) which mediate recognition of 5' splice sites. The P.I. has isolated cDNA and genomic clones encoding the hU1-70K protein, a specific component of U1 snRNP that may be directly involved in 5'splice site recognition. He has already demonstrated that this protein binds RNA and have begun to map the RNA-binding sites in the protein. He now proposes to characterize the structure and expression of the human gene encoding the hU1-70K snRNP protein, to define the sites in the U1-70K protein that mediate its interaction with U1 snRNA, pre-mRNA, and other snRNP proteins, and it determine how specific substitutions in the hU1-70K protein affect 5' splice site recognition by U1 snRNP. He also plans to perform similar studies of other U1 snRNP proteins. These studies should thus be of profound importance for elucidating the process of 5' splice site recognition by U1 snRNP. DNA of living cells codes for cellular proteins via the intermediation of RNA. The RNA that is transcribed from the DNA is larger than the functional form that is translated into proteins. The processing of the transcribed form to the functional form involves the removal of segments of RNA from the interior of the molecule, a process known as splicing. The investigator has identified one of the components of the splicing machinery and is study the manner in which it acts.
