Ribonucleoprotein complexes in gene expression: Remodeling events and common components in nuclear and mitochondrialmRNA maturation
Messenger RNAs associate co-transcriptionally with several proteins to form ribonucleoprotein (RNP) complexes. Several lines of evidence indicate that these RNP complexes undergo substantial changes in protein composition as the RNAs are processed in the nucleus and exported to the cytoplasm. The work presented in this dissertation describes the isolation, from HeLa cells, of three distinct types of pre-mRNP and mRNP complexes associated with hnRNP A1, a shuttling hnRNP protein thought to bind RNAs from their transcription through their processing and export. Based on their RNA and protein composition, these complexes are likely to represent RNPs at distinct stages in the nucleocytoplasmic shuttling pathway of hnRNP A1 with its bound RNAs. Interestingly, one of these complexes exhibits characteristics of RNPs at late stages of nuclear maturation and likely arises from remodeling of the pre-mRNA containing hnRNP complexes. This remodeling includes removal of non-shuttling hnRNP proteins and recruitment of alternatively spliced isoforms of hnRNP proteins and of LRP130, a recently described PPR motif-containing protein
Thesis, Dissertation, English, 2003