Autoantigens/chemistry; Carrier Proteins/chemistry; Proline/chemistry; Ribonucleoproteins, Small Nuclear/chemistry; Spliceosomes/metabolism; Adaptor Proteins, Signal Transducing; Alternative Splicing; Amino Acid Motifs; Amino Acid Sequence; Autoantigens/metabolism; Carrier Proteins/metabolism; Cell Membrane/metabolism; Databases as Topic; Glutathione Transferase/metabolism; Glycine/chemistry; Green Fluorescent Proteins; HeLa Cells; Humans; Jurkat Cells; Kinetics; Ligands; Luminescent Proteins/metabolism; Magnetic Resonance Spectroscopy; Microscopy, Fluorescence; Molecular Sequence Data; Peptides/chemistry; Protein Binding; Protein Conformation; Protein Structure, Tertiary; Ribonucleoproteins, Small Nuclear/metabolism; Signal Transduction; Software; Transfection; snRNP Core Proteins