Reaction: IKKB phosphorylates SNAP23
- in pathway: ER-Phagosome pathway
A major reserve of MHC-I in dendritic cells reside within the endocytic recycling compartments (ERC). MHC-I trafficking to the ERC is regulated by the activity of Rab11a and subsequent trafficking from ERC to phagosomes is controlled by TLR-MyD88-IKK2-dependent phosphorylation of phagosomal SNAP23. Toll-like receptor (TLR) signalling regulate cross-presentation as they regulate phagocytosis and phagolysosomal fusion (Nair et al. 2011). MHC-I bearing ERC are enriched with R-SNAREs like RAB11a, VAMP3, and VAMP8. These SNARE molecules can interact with Q-SNARE SNAP23 present on phagosomes and this mediates membrane fusion. This interaction of SNAP23 with R-SNAREs require phosphorylation of SNAP23 (on Ser-95) by IKK2, and IKK2 is activated by TLR signalling. SNAP23 phosphorylation may increase SNAP23 binding to SNAREs. It may also regulate platelet and mast cell secretion (Karim et al. 2013, Suziki & Verma 2008).
Reaction - small molecule participants:
ADP [cytosol]
ATP [cytosol]
Reactome.org reaction link: R-HSA-8863895
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Reaction input - small molecules:
ATP(4-)
Reaction output - small molecules:
ADP(3-)
Reactome.org link: R-HSA-8863895