# HISTORY
25 Mar 2016: Updated by: TOUCHUP-v1.15
16 Mar 2016: Updated by: TOUCHUP-v1.14

# molecular_function

# cellular_component
20140729: Eukaryota_PTN000380174 is found in cilium (GO:0005929) 
20140729: Eukaryota_PTN000380174 is found in intraciliary transport particle A (GO:0030991) 

# biological_process
20140729: Eukaryota_PTN000380174 participates in intraciliary retrograde transport (GO:0035721) 
20140729: Eukaryota_PTN000380174 participates in protein localization to cilium (GO:0061512) 
20140729: Eukaryota_PTN000380174 participates in cilium morphogenesis (GO:0060271) 

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

# NOTES
This family contains the TTC21 subunit of the core of the intraciliary transport complex IFT A. The IFT A complex is found in all types of cilia, both primary cilia and motile cilia and is involved in intraciliary retrograde transport (from the base to the tip) within the cilium (PMID:23945166).
Note that in the vertebrates, there is a duplication producing TTC21A and TTC21B. TTC21B is experimentally shown in both human and mouse to be present in IFT A, but TTC21A is not experimentally characterized yet (as of 7/29/14). As the MSA looks very good across the whole family, I am propagating annotations from the TTC21B subclade to the root node. Perhaps TTC21A has a specialized localization such as testis, as is commonly seen in other protein families.
I did not propagate the annotation to "regulation of transcription from RNA polymerase II promoter" to the HUMAN_TTC21B because in looking at the paper, it did not appear to be a very specific effect. In addition, this has not been experimentally observed in any other species.

# 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).