Summary: PANTHER IBA to nucleus is consistent with Pno1's conserved role as a nuclear/nucleolar and nucleocytoplasmic ribosome biogenesis factor.

Reason: Pno1 acts in nuclear and nucleolar stages of SSU biogenesis and has direct experimental nuclear/nucleolar localization support.

Summary: Automated RNA-binding annotation is supported by Pno1 KH domains and by direct evidence for binding pre-rRNA/ITS1.

Reason: RNA binding is a core molecular function for Pno1, though the more specific rRNA primary transcript binding term is preferred when available.

Summary: UniProt/ARBA nucleolus mapping is consistent with Pno1 function in early nucleolar SSU processome assembly and pre-rRNA processing.

Reason: The nucleolus is a supported compartment for Pno1 during early ribosome biogenesis.

Summary: Cytoplasmic localization is consistent with Pno1 shuttling and late cytoplasmic pre-40S maturation.

Reason: Pno1 functions after pre-40S export as part of late 18S rRNA maturation and quality-control gating.

Summary: Broad automated ribosome biogenesis annotation accurately summarizes the experimentally supported Pno1 role in SSU/pre-40S assembly and maturation.

Reason: Pno1 is a ribosome biogenesis factor; more specific annotations capture SSU-rRNA maturation, pre-40S export, and ribosome assembly.

Summary: ComplexPortal direct assay evidence places Pno1 in the nucleolus/SSU processome context.

Reason: Nucleolar localization matches Pno1's early SSU processome and pre-rRNA processing roles.

Summary: Curated statement evidence supports Pno1 as a specific SSU processome component linked to SSU-rRNA maturation.

Reason: The annotation is consistent with multiple yeast studies showing defects in pre-rRNA processing when Pno1/Dim2/Rrp20 is perturbed.

Summary: Mutant phenotype evidence supports Dim2/Pno1 involvement in pre-40S export from the nucleus.

Reason: Pno1 contains a conserved export-related region and perturbation causes pre-40S export defects, making this a core process annotation.

Summary: Direct assay evidence shows Dim2/Pno1 binds pre-rRNA through its KH domain at the 5' end of ITS1.

Reason: This is the most specific experimentally supported molecular function for Pno1 and should be considered core.

Summary: Mutant phenotype evidence supports Dim2/Pno1 function in cotranscriptional ribosome assembly and pre-40S maturation.

Reason: Pno1 coordinates pre-rRNA binding, pre-40S export, and later maturation, so ribosome assembly is appropriate.

Summary: High-throughput direct assay evidence identifies Pno1/Rrp20 with 90S preribosomal particles.

Reason: This component annotation is consistent with Pno1's early SSU processome role.

Summary: The 2002 Nob1/Pno1 study connected pno1 defects with Pre6p accumulation and proteasome maturation, but subsequent literature and UniProt support a primary SSU ribosome biogenesis role for Pno1.

Reason: PMID:12502737 directly reports pno1 mutant proteasome maturation defects, but later Pno1/Dim2 literature supports ribosome biogenesis, pre-rRNA processing, and pre-40S maturation as the conserved core function. This proteasome assembly annotation is therefore retained only as a non-core/over-annotated phenotype from an older model.

Summary: The protein-interaction basis for proteasome assembly is not sufficient to override the now well-supported Pno1 role in SSU/pre-40S maturation.

Reason: The original paper did observe proteasome assembly defects in pno1 mutants, but the current weight of evidence places Pno1 as a Dim2/Rrp20 ribosome biogenesis factor. The proteasome annotation should therefore be treated as an over-annotated non-core phenotype rather than a primary molecular role.

Summary: RRP20/PNO1 mutant phenotypes impair early pre-rRNA cleavages, including ITS1 processing that separates SSU from LSU rRNA precursors.

Reason: Pno1 is required for proper pre-rRNA processing as part of the SSU maturation pathway, although it is not itself the nuclease.

Summary: PNO1/RRP20 mutant evidence supports a requirement for proper pre-18S rRNA processing and mature SSU-rRNA formation.

Reason: The annotation captures a core process consequence of Pno1 function in SSU maturation.

Summary: Direct assay evidence supports nuclear localization of Pno1.

Reason: Nuclear localization is consistent with Pno1's early pre-rRNA processing and pre-40S export roles.

Summary: Direct GFP localization evidence places Yor145c/Pno1 in the nucleolus.

Reason: Nucleolar localization is appropriate for an early SSU processome and pre-rRNA processing factor.

Summary: The old proteasome study supports a Pno1-Nob1 interaction and pno1 proteasome phenotypes, not direct unfolded-protein binding by Pno1.

Reason: Tone and Toh-e showed that Pno1p forms a complex with Nob1p and that a pno1-1 mutant has proteasome maturation phenotypes, but their chaperone model was for Nob1p rather than a direct Pno1 unfolded-protein-binding activity. The closest Pno1 result in the paper is that pno1-1 blocks nuclear transfer of immature 20S proteasome precursors, a requirement-for-transport phenotype rather than a Pno1 binding assay. Subsequent yeast studies established Dim2/Pno1 as a KH-domain SSU/pre-40S assembly factor that binds pre-rRNA and helps Nob1 with final 18S rRNA maturation, so generic unfolded-protein binding should not be carried forward as a Pno1 molecular function.