AHCYL1 Antibody - #DF12091

Multifaceted cellular regulator which coordinates several essential cellular functions including regulation of epithelial HCO3(-) and fluid secretion, mRNA processing and DNA replication. Regulates ITPR1 sensitivity to inositol 1,4,5-trisphosphate competing for the common binding site and acting as endogenous 'pseudoligand' whose inhibitory activity can be modulated by its phosphorylation status. In the pancreatic and salivary ducts, at resting state, attenuates inositol 1,4,5-trisphosphate-induced calcium release by interacting with ITPR1. When extracellular stimuli induce ITPR1 phosphorylation or inositol 1,4,5-trisphosphate production, dissociates of ITPR1 to interact with CFTR and SLC26A6 mediating their synergistic activation by calcium and cAMP that stimulates the epithelial secretion of electrolytes and fluid (By similarity). Also activates basolateral SLC4A4 isoform 1 to coordinate fluid and HCO3(-) secretion. Inhibits the effect of STK39 on SLC4A4 and CFTR by recruiting PP1 phosphatase which activates SLC4A4, SLC26A6 and CFTR through dephosphorylation (By similarity). Mediates the induction of SLC9A3 surface expression produced by Angiotensin-2. Depending on the cell type, activates SLC9A3 in response to calcium or reverses SLC9A3R2-dependent calcium inhibition. May modulate the polyadenylation state of specific mRNAs, both by controlling the subcellular location of FIP1L1 and by inhibiting PAPOLA activity, in response to a stimulus that alters its phosphorylation state. Acts as a (dATP)-dependent inhibitor of ribonucleotide reductase large subunit RRM1, controlling the endogenous dNTP pool and ensuring normal cell cycle progression. In vitro does not exhibit any S-adenosyl-L-homocysteine hydrolase activity (By similarity).

Phosphorylated at Ser/Thr residues between Ser-68 and Thr-72 in the PEST region: required for interaction with dATP-bound RRM1 and ITPR1. Phosphorylation at Ser-68 by PRKD1 and CAMK4 is required for further phosphorylations by CSNK1A1. Phosphorylation is induced by oxidative stress. Probably phosphorylated by CAMK2A; phosphorylation at Ser-68 may be required for interaction with SLC9A3.

Endoplasmic reticulum. Cytoplasm>Cytosol. Microsome. Apical cell membrane.
Note: Associates with membranes when phosphorylated, probably through interaction with ITPR1.

Expressed in dendritic cells.

Forms multimers. Forms heteromultimers with AHCYL2 (via the C-terminal region). Interacts (when phosphorylated) with ITPR1 (when not phosphorylated); the interaction suppresses inositol 1,4,5-trisphosphate binding to ITPR1. Interacts with CFTR and SLC26A6; the interactions take place once AHCYL1 is released from ITPR1 and increase CFTR and SLC26A6 activities (By similarity). Interacts with RRM1; in a phosphorylation- and (dATP)-dependent manner. Interacts (via PEST domain when phosphorylated) with SLC4A4 isoform 1 but not isoform 2; the interaction increases SLC4A4 isoform 1 activity. Interacts (when phosphorylated) with SLC9A3; the interaction is required for SLC9A3 apical location and activity. Interacts (when phosphorylated) with FIP1L1; the interaction is direct and associates AHCYL1 with the CPSF complex and RNA. Interacts with PAPOLA.

The PEST region is essential for the interaction with ITPR1, and, when phosphorylated, is also the RRM1-binding region. The PDZ-binding region is required for maximal interaction with ITPR1 and is also responsible for the IP3-insensitive interaction with ITPR1 (By similarity).

Belongs to the adenosylhomocysteinase family.