Table 1. List of common and possible PIKK regulators in mammals.
| Molecule | Domain/Motif | Character and related cellular process | Possible phosphorylation site by PIKKs** | |
|---|---|---|---|---|
| Common PIKK regulators |
RUVBL1 (RuvB-like 1) |
AAA+ domain, Walker A, WalkerB motif |
AAA+ family proteins, ATPase/DNA helicase activity, form a hexameric complex, transcriptional regulation, RNA modification/biogenesis, telomere maintenance, DNA repair, spindle formation, Hsp90 cofactor, NMD |
- |
| RUVBL2 (RuvB-like 2) |
Prediction & report: Ser220 (ref. 105) |
|||
| Hsp90 (Heatshock protein 90) |
Histidine kinase-like ATPases domain |
conserved molecular chaperone, ATPase, promotes protein folding/structural maturation/assembly/transport of specific client proteins |
Prediction & report: Thr297 (ref. 105) |
|
| Tel2 (telomere maintenance 2) |
- |
replication checkpoint, DNA damage response/checkpoint |
- |
|
| SMG-10/Tti1 (Tel2 interacting protein 1) |
HEAT repeat |
Tel2 complex component, DNA damage response/checkpoint |
prediction: Ser391 |
|
| Tti2 (Tel2 interacting protein 2) |
- |
Tel2 complex component, DNA damage response/checkpoint |
- |
|
| Possible PIKK regulators |
RPAP3 (RNAPII-Associated Protein 3) |
TPR motif |
RNA polymerase associated protein, Hsp90 cofactor, UV-induced DNA damage response and cell survival, TNF-α and cycloheximide-induced apoptosis |
prediction: Ser116 Ser481 |
| |
NOP17 (Nucleolar protein 17) |
PIH1 domain |
pre-rRNA processing/RNA modification, Hsp90 cofactor |
- |
| |
URI/RMP (Unconventional prefoldine RPB5 interactor/RPB5 mediating protein) |
Prefoldin α domain |
unconventional prefoldin, transcriptional regulation, regulation of survival signaling at mitocochondria |
phosphrylated at Ser371 by p70 S6K, downstream of mTOR (ref. 161) |
| RPB5 (RNA polymerase II subunit 5) |
- |
shared subunits of all three RNA polymerases, transcriptional regulation, NMD |
prediction: T29 |
|
| Monad/WDR92 (WD repeat domain 92) | WD40 domain | RNA polymerase associated protein, TNF-α and cycloheximide-induced apoptosis | - |
Notes: *All molecules are evolutionarily conserved in eukaryote; **possible phosphorylation sites were predicted by the scansite program (http://scansite.mit.edu/) with high stringency. Aabbreviations; AAA+, ATPase associated diverse cellular activities; TPR, tetratricopeptide repeat; HEAT, Huntingtin, elongation factor 3, A subunit of protein phosphatase 2A, and TOR1.