LMPD Database

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LMP001255

UniProt Annotations

Entry Information
Gene NameATPase, class I, type 8B, member 1
Protein EntryAT8B1_MOUSE
UniProt IDQ148W0
SpeciesMouse
Comments
Comment typeDescription
Catalytic ActivityATP + H(2)O + phospholipid(Side 1) = ADP + phosphate + phospholipid(Side 2).
Disruption PhenotypeMice have unimpaired bile secretion, and no liver damage, but show mild abnormalities including depressed weight at weaning and elevated serum bile salt levels. Do not suffer from jaundice or diarrhea and have normal serum bilirubin levels and normal liver enzyme activities, except for mildly elevated serum AST (aspartate aminotransferase) activity. Display unimpaired transhepatic bile salt transport and are resistant to bile salt-induced cholestasis. Upon bile salt feeding, demonstrate serum bile salt accumulation, hepatic injury and expansion of the systemic bile salt pool and this failure of bile salt homeostasis occurrs in the absence of any defect in hepatic bile secretion. {ECO:0000269|PubMed:14976163}.
FunctionCatalytic component of a P4-ATPase flippase complex which catalyzes the hydrolysis of ATP coupled to the transport of aminophospholipids from the outer to the inner leaflet of various membranes and ensures the maintenance of asymmetric distribution of phospholipids. Phospholipid translocation seems also to be implicated in vesicle formation and in uptake of lipid signaling molecules. May play a role in asymmetric distribution of phospholipids in the canicular membrane. Plays a role in bile salt homeostasis. In cooperation with ABCB4 may be involved in establishing integrity of the canalicular membrane thus protecting hepatocytes from bile salts. Involved in the microvillus formation in polarized epithelial cells; the function seems to be independent from its flippase activity. Required for the preservation of cochlear hair cells in the inner ear. Required for the preservation of cochlear hair cells in the inner ear. According PubMed:20852622 is proposed to act as cardiolipin transporter during inflammatory injury; the function is questioned by PubMed:21475228. {ECO:0000269|PubMed:14976163, ECO:0000269|PubMed:19478059, ECO:0000269|PubMed:20852622, ECO:0000269|PubMed:21475228, ECO:0000269|PubMed:21820390}.
SimilarityBelongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IV subfamily. {ECO:0000305}.
Subcellular LocationCell membrane {ECO:0000269|PubMed:20852622}; Multi-pass membrane protein {ECO:0000269|PubMed:20852622}. Apical cell membrane {ECO:0000250}. Cell projection, stereocilium {ECO:0000269|PubMed:20852622}. Endoplasmic reticulum {ECO:0000250}. Golgi apparatus {ECO:0000250}. Note=Exit from the endoplasmic reticulum requires the presence of TMEM30A or TMEM30B.
SubunitComponent of a P4-ATPase flippase complex which consists of a catalytic alpha subunit and an accessory beta subunit. The probable flippase ATP8B1:TMEM30A complex can form an intermediate phosphoenzyme in vitro. Also interacts with beta subunit TMEM30B (By similarity). {ECO:0000250}.
Tissue SpecificityHepatocytes, bile duct, intestinal epithelial cells (cholangiocytes and ileocytes), and pancreatic acinar cells. {ECO:0000269|PubMed:14976163}.