calsyntenin-3; alcadein-beta; alc-beta (CLSTN3 CS3 KIAA0726)

Function

• may modulate Ca+2-mediated postsynaptic signals
• complex formation with APBA2 & APP
• stabilizes APP metabolism & enhances APBA2-mediated suppression of beta-APP40 secretion, due to retardation of intracellular APP maturation
• proteolytically processed under normal cellular conditions
• primary zeta-cleavage generates a large extracellular (soluble) N-terminal domain (salc) & a short C-terminal transmembrane fragment (CTF1)
• secondary cleavage catalyzed by gamma-secretase within the transmembrane domain releases the beta-alc-beta chain in the extracellular milieu & produces an intracellular fragment (alcICD). this processing is strongly suppressed in the tripartite complex formed with APBA2 & APP, which seems to prevent the association with gamma-secretase
• directly interacts with APBA2. forms a tripartite complex with APBA2 & APP
• interacts with low affinity with KLC1

Structure

• binds synaptic Ca+2 with its cytoplasmic domain
• contains 2 cadherin domains

Compartment

• cell membrane; single-pass type 1 membrane protein (putative)
• endoplasmic reticulum membrane
• Golgi membrane
• most prominent in the postsynaptic specializations of asymmetric (type 1) synapses with both axodendritic & axospinous localization (putative)

Expression

• expressed predominantly in the brain & in kidney
• low levels in heart, skeletal muscle, liver, placenta, pancreas & lung
• predominant expression inbrain, & only marginal in kidney
• in brain, present throughout all cortical layers
  • highest levels in GABAergic neurons (based on morphology & distribution pattern)

More general terms

• calsyntenin

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9746
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9746
• OMIM: https://mirror.omim.org/entry/611324
• UniProt: http://www.uniprot.org/uniprot/Q9BQT9.html