"We refer to members of this family as activated in blocked UPR (abu)"

"Nine of these encode highly similar, novel proteins with a hydrophobic NH2-terminal signal sequence, a potential transmembrane domain, and a short COOH-terminal cytoplasmic domain"

"Immunostaining of the FLAG-tagged ABU-1–expressing COS1 cells with anti-FLAG antibodies showed a diffuse reticular pattern that colocalized with the ER marker ribophorin I"

"RNA-mediated interference (RNAi) inactivation of a representative abu family member, abu-1 (AC3.3), activated the ER stress marker hsp-4::gfp in otherwise normal animals and killed 50% of ER-stressed ire-1 and xbp-1 mutant animals"

"It is possible therefore that the ABU proteins may be playing a similar role within the endomembrane system, perhaps by binding to altered ER client proteins and modulating their intracellular fate"

"These observations suggest that abu-1 (and possibly other abu genes) and sel-1 perform partially redundant functions in animals with a blocked UPR"

"PQN/ABU proteins involved in a noncanonical UPR response are required for proper defense to pathogen infection in Caenorhabditis elegans."

"abu-1 overexpression rescues the enhanced susceptibility to S. enterica of ced-1(e1735) mutants (Figure 6D)."

"the pharyngeal invasion of ced-1(e1735) animals is comparable to that of abu-1 RNAi and abu-11 RNAi animals, which greatly contrasts to the limited pharyngeal invasion observed in wild-type nematodes grown on control RNAi plates (Figure 5G)."

"OCTR-1, a putative octopamine G protein-coupled catecholamine receptor (GPCR, G protein-coupled receptor), functioned in sensory neurons designated ASH and ASI to actively suppress innate immune responses by down-regulating the expression of noncanonical UPR genes pqn/abu in nonneuronal tissues."

"Instead, the strongest data support ABU-1 as an **ER/endomembrane proteostasis factor** that protects cells/animals from ER stress, especially when canonical UPR signaling is defective"

"ABU-1 is described as a **type I single-pass membrane protein** family member, with an **N-terminal signal sequence**, a **luminal domain**, a **transmembrane segment**, and a short **C-terminal cytosolic tail**"

"No enzymatic reaction, transporter substrate, or ligand-binding specificity has been established for ABU-1 in the retrieved evidence."

"Reporter analyses indicate strong basal **pharynx/head expression** from late larval stages to young adult, with low basal intestinal expression that becomes stress inducible"

"The same work provides functional evidence that **ABU-1 contributes to resistance to live-pathogen challenge**: abu-1 RNAi increases *Salmonella* pharyngeal invasion, and ABU-1 overexpression can rescue the increased susceptibility of **ced-1(e1735)** mutants"

"Sun et al. (2011) described a neuro-immune regulatory mechanism in which the neuronal GPCR **OCTR-1** suppresses peripheral innate immunity partly by down-regulating noncanonical UPR genes described as **pqn/abu**."