This thesis by Stefanie Gerstberger focuses on two main aspects: the comprehensive analysis of human RNA-binding proteins (RBPs) and the characterization of the DEDDh RNA exonuclease NEF-SP in the 3' end maturation of 28S ribosomal RNA (rRNA). 1. **A Census of Human RNA-Binding Proteins**: Gerstberger developed a comprehensive catalog of 1,542 manually curated RBPs, categorized their interactions with different classes of RNA, and investigated their evolutionary patterns, abundance, and tissue-specific expression. The analysis revealed insights into the regulatory pathways and disease phenotypes associated with RBPs involved in the same RNA metabolic pathways. 2. **Characterization of the DEDDh RNA Exonuclease NEF-SP**: Gerstberger characterized the function of the uncharacterized, highly tissue-specific RNA exonuclease NEF-SP in Drosophila melanogaster. The study demonstrated that NEF-SP is involved in the exonucleolytic trimming of the 3' external transcribed spacer (3'ETS) of the large 47S rRNA precursor, which is essential for 28S rRNA maturation. The loss of NEF-SP function leads to developmental defects in the gonads, highlighting its critical role in rRNA biogenesis. The thesis provides a foundational understanding of the system-wide analysis of PTGR factors in humans and their conserved homologs in other species, as well as detailed mechanistic insights into the 3' end maturation of 28S rRNA in higher eukaryotes.This thesis by Stefanie Gerstberger focuses on two main aspects: the comprehensive analysis of human RNA-binding proteins (RBPs) and the characterization of the DEDDh RNA exonuclease NEF-SP in the 3' end maturation of 28S ribosomal RNA (rRNA). 1. **A Census of Human RNA-Binding Proteins**: Gerstberger developed a comprehensive catalog of 1,542 manually curated RBPs, categorized their interactions with different classes of RNA, and investigated their evolutionary patterns, abundance, and tissue-specific expression. The analysis revealed insights into the regulatory pathways and disease phenotypes associated with RBPs involved in the same RNA metabolic pathways. 2. **Characterization of the DEDDh RNA Exonuclease NEF-SP**: Gerstberger characterized the function of the uncharacterized, highly tissue-specific RNA exonuclease NEF-SP in Drosophila melanogaster. The study demonstrated that NEF-SP is involved in the exonucleolytic trimming of the 3' external transcribed spacer (3'ETS) of the large 47S rRNA precursor, which is essential for 28S rRNA maturation. The loss of NEF-SP function leads to developmental defects in the gonads, highlighting its critical role in rRNA biogenesis. The thesis provides a foundational understanding of the system-wide analysis of PTGR factors in humans and their conserved homologs in other species, as well as detailed mechanistic insights into the 3' end maturation of 28S rRNA in higher eukaryotes.