# HISTORY
26 Mar 2016: Updated by: TOUCHUP-v1.15
17 Mar 2016: Updated by: TOUCHUP-v1.14

# molecular_function
20140908: node_PTN000506776 has function rRNA primary transcript binding (GO:0042134) 
20140930: Eukaryota_PTN000506837 has function snoRNA binding (GO:0030515) 

# cellular_component
20140930: node_PTN000506776 is found in nucleolus (GO:0005730) 
20140908: Eukaryota_PTN000506777 is found in preribosome, large subunit precursor (GO:0030687) 
20140908: Eukaryota_PTN000506837 is found in small-subunit processome (GO:0032040) 
20140930: Eukaryota_PTN000506837 is found in Mpp10 complex (GO:0034457) 

# biological_process
20140908: node_PTN000506776 participates in rRNA processing (GO:0006364) 
20140908: Eukaryota_PTN000506777 participates in ribosomal large subunit assembly (GO:0000027) 
20140930: Eukaryota_PTN000506777 participates in maturation of LSU-rRNA (GO:0000470) 
20140930: Eukaryota_PTN000506777 participates in maturation of 5.8S rRNA (GO:0000460) 

# WARNINGS - THE FOLLOWING HAVE BEEN REMOVED FOR THE REASONS NOTED

# NOTES
This family is comprised of two clades of RNA binding proteins involved in rRNA processing. The RPF1 clade is involved in ribosomal large subunit biogenesis and rRNA processing to generate the large subunit RNAs, the LSU rRNA and the small rRNA generally referred to as the 5.8S rRNA. The IMP4 clade is involved in ribosomal small subunit biogenesis and rRNA processing to generate the small subunit RNA, the LSU rRNA.
RPF1 clade
========
RPF1 from S. cerevisiae is well characterized as a factor involved in large ribosomal subunit biogenesis and maturation of the rRNAs that become part of the large subunit, the LSU-rRNA and the 5.8S rRNA. Note that there is some variability in the sizes and sometimes even the number of mature rRNAs that are produced from primary rRNA transcript to become part of the large ribosomal subunit. Thus, the largest rRNA present in the large ribosomal subunit is referred to as the LSU rRNA; the 5.8S rRNA is often referred to by that name, even in some cases where it is a different size.
IMP4 clade
========
This clade comprises the IMP4 subunits of the ribosomal Small Subunit Processome, also called the SSU Processome, a large complex which is involved in the initial cleavages of the primary rRNA transcript to separate the small ribosomal subunit (SSU) rRNA from the remainder of the transcript and the biogenesis of the small ribosomal subunit.
The SSU processome was originally identified and characterized from S. cerevisiae (Dragon et al. 2002, PMID:12068309; Gallagher et al. 2004, PMID:15489292; Bernstein et al. 2004, PMID:15590835; and reviewed in Phipps et al. 2011, PMID:21318072). As of September 2014, it has begun to be characterized experimentally from other species such as human (Turner et al. 2012, PMID:22418842; Sato et al. 2013, PMID:24219289; and Hu et al. 2011, PMID:21078665), zebrafish (Wilkins et al. 2013, PMID:24147052), and mouse (Gallenberger et al. 2011, PMID:21051332).
The IMP4 subunit is a confirmed subunit of the SSU processome, and specifically part of the Mpp subcomplex (Phipps et al. 2011, PMID:21318072).
Feng et al. 2013 (PMID:24214024) performed an extensive computational analysis from 77 completely sequenced eukaryotic genomes, including representatives of the five eukaryotic supergroups: Opisthokonts, Amoebozoa, Plantae, Excavates, and Chromalveolates, and compared these to sequences from both prokaryotic and Archaeal species for all 51 confirmed and 26 likely SSU processome subunits in S. cerevisiae as indicated in Phipps et al. 2011 (PMID:21318072). In addition, Srivastava et al. have identified SSU processome subunits in the parasitic protist Entamoeba histolytica (PMID:24631428).
IMP4 is one of the 51 confirmed proteins of the S. cerevisiae SSU processome (Phipps et al. 2011, PMID:21318072)) and is highly conserved across the 77 eukaryotic species, as listed in Table 1 of Feng et al. 2013 (PMID:24214024). It is also found in the parasitic protist Entamoeba histolytica (Srivastava et al. 2014, PMID:24631428).

# REFERENCE
Annotation inferences using phylogenetic trees
The goal of the GO Reference Genome Project, described in PMID 19578431, is to provide accurate, complete and consistent GO annotations for all genes in twelve model organism genomes. To this end, GO curators are annotating evolutionary trees from the PANTHER database with GO terms describing molecular function, biological process and cellular component. GO terms based on experimental data from the scientific literature are used to annotate ancestral genes in the phylogenetic tree by sequence similarity (ISS), and unannotated descendants of these ancestral genes are inferred to have inherited these same GO annotations by descent. The annotations are done using a tool called PAINT (Phylogenetic Annotation and INference Tool).