barttin (BSND, BART)

Function

• beta-subunit for CLCNKA & CLCNKB Cl- channels
• in kidney, CLCNK/BSND heteromers mediate Cl- reabsorption by facilitating its basolateral efflux
• in stria vascularis of inner ear, CLCNK/BSND channels drive K+ secretion by recycling Cl- for basolateral SLC12A2 cotransporter
• interacts with CLCNK channel
• forms heteromers with CLCNKA in the thin ascending limb of the loop of Henle & with CLCNKB in the thick ascending limb & more distal segments

Compartment

basolateral cell membrane

Alternative splicing

named isoforms=2

Expression

• expressed primarily in kidney
• expressed in specific nephron segments & in stria vascularis of inner ear

Pathology

• defects in BSND are the cause of antenatal Bartter syndrome type 4

More general terms

• transmembrane 2 protein

Database

• OMIM: https://mirror.omim.org/entry/602522
• OMIM: https://mirror.omim.org/entry/606412
• UniProt: http://www.uniprot.org/uniprot/Q8WZ55.html