Function
Sequestosome (SQS) or p62, is required for the formation and autophagic degredation of polyubiquitin-containg bodies. SQS may regulate signaling cascades through ubiquitination[1].
Structural highlights
SQS is a multi-domain protein. SQS domain structure includes:
PB1 domain which contains Phox and Berm1
ZZ-type zinc finger
SMIR – SOD interaction domain
TB – TRAF6 binding motif
LC3 – microtubule-associated protein 1 light chain 3B
LIR – interaction region
UBA – ubiquitin association domain.
Relevance
SQS is associated with fibrillary tangles in Alzheimer disease[2].
3D structures of sequestosome
Updated on 25-August-2016
1q02, 2jy7, 2jy8, 2k0b, 2knv – SQS UBA domain – human - NMR
3b0f – mSQS UBA domain – mouse
2rru – mSQS UBA domain - NMR
2ktr – rSQS PB1 domain – rat - NMR
2kkc – rSQS PB1 domain (mutant) - NMR
3ade – mSQS + KEAP-1 – mouse
4mjs – hSQS-1 PB1 domain + protein kinase C zeta type
4uf8, 4uf9 – hSQS-1 PB1-P62 domain – Cryo EM
