ABCB1
ATP binding cassette subfamily B member 1
Gene summary
A protein-coding gene on chromosome 7 (drug and xenobiotic transporters). The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes.
Source: NCBI Gene, accessed 2026-10-07.
Protein reference (UniProt)
- Protein
ATP-dependent translocase ABCB1
- Function
Translocates phospholipids and drugs across the membrane. Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins. Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells. May contribute to hepatobiliary and renal excretion of etiocholanolone-3-glucuronate. Appears to have very low activity toward testosterone, androsterone and dihydrotestosterone glucuronates.
- Subcellular location
Cell membrane; Apical cell membrane; Cytoplasm.
- Tissue specificity
Expressed in small intestine. Expressed in liver, kidney and brain.
- Associated conditions
Inflammatory bowel disease 13 (IBD13); Encephalopathy, acute transient (ENPAT).
Source: UniProtKB/Swiss-Prot P08183, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.
Why its pathway is in the library
Transporters set systemic exposure to finasteride/SSRIs and clear conjugated steroid metabolites — directly relevant to both drug pharmacokinetics and Powers' clearance-centered PFS mechanism.
Written for the whole drug transporters family, not for ABCB1 specifically.
Mentioned in 3 corpus records
- Powers · Reddit commentCurated Powers pick
Re: Had another random pssdpfs thought about the…
u/drwillpowers · r/DrWillPowers
Reply to a community member's glucuronidation-theory thought about sulfation labs. Powers notes the discussed factor interacts with androgen production and ABCC-family transporters (he believes ABCB1 specifically, with the caveat that he read it long ago)…
ABCB1LRP2UGT2B15UGT2B17UGT2B7PRH-13982026-04-01T15:22:34ZPFSPSSDPowers Reddit history - Peer-reviewed paper
Influence of CYP2C19, CYP2D6, and ABCB1 Gene Variants and Serum Levels of Escitalopram and Aripiprazole on Treatment-Emergent Sexual Dysfunction: A Canadian Biomarker Integration Network in Depression 1 (CAN-BIND 1) Study
Farhana Islam, Leen Magarbeh, Samar S. M. Elsheikh, Stefan M. Kloiber, Caroline Wanderley Espinola, Venkat Bhat, Benicio Noronha Frey… · The Canadian Journal of Psychiatry
In 178 adults with major depressive disorder treated with escitalopram (weeks 0-8), nonresponders were augmented with aripiprazole while responders continued escitalopram alone (weeks 8-16), with sexual function and satisfaction tracked on the SexFX scale…
ABCB1CYP2C19CYP2D6MECH-0352023 (epub Oct 2023)PSSDSystems review · Oct 2026 - Peer-reviewed paper
ABCB1 gene variants influence tolerance to selective serotonin reuptake inhibitors in a large sample of Dutch cases with major depressive disorder
Onno L. de Klerk, Ilja Maria Nolte, Pierre M. Bet, Fokko J. Bosker, Harold Snieder, Johan A. den Boer, Richard Bruggeman, Witte J.G… · The Pharmacogenomics Journal
P-glycoprotein, the ABCB1-encoded efflux pump at the blood-brain barrier, controls how much of an SSRI substrate reaches the brain. In 424 patients with major depressive disorder from the Netherlands Study of Depression and Anxiety (NESDA), six ABCB1 variants…
ABCB1MECH-0362013 (epub May 2012)PSSDSystems review · Oct 2026
Also in drug and xenobiotic transporters
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chr 10· Drug transporters· 6 records - ABCC3Powers
ATP binding cassette subfamily C member 3
chr 17· Drug transporters· 5 records - ABCC5Powers
ATP binding cassette subfamily C member 5
chr 3· Drug transporters· 3 records - SLCO1B1Powers
solute carrier organic anion transporter family member 1B1
chr 12· Drug transporters· 4 records - SLC18A2
solute carrier family 18 member A2
chr 10· Drug transporters· 1 record - SLCO1B3
solute carrier organic anion transporter family member 1B3
chr 12· Drug transporters· 1 record - ABCB11
ATP binding cassette subfamily B member 11
chr 2· Drug transporters· Pathway candidate
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