Carboxylesterase 1 pseudogene 1 (CES1P1)

Carboxylesterase 1 pseudogene 1 (CES1P1) is a human pseudogene located in a tail-to-tail orientation with the functional carboxylesterase 1 (CES1) gene[3]. CES1P1 is classified as a pseudogene because it harbors a premature stop codon in exon 4, making it incapable of producing an active or functional carboxylesterase enzyme[3]. While the canonical CES1 enzyme metabolizes a broad array of ester- and amide-containing drugs and xenobiotics[1][2][3], CES1P1 does not contribute to these functions and is not considered a therapeutic target, biomarker, or drug-metabolizing enzyme[3]. However, there exists a rare variant, CES1P1 VAR, that is a functional coding gene and can produce enzyme, but its transcriptional activity is considerably lower than CES1 and it is not a significant drug metabolism determinant in vivo[3]. CES1P1 is sometimes referred to by alternative names, many of which derive from its similarity to other carboxylesterase genes or from unconfirmed historical assignments. Unlike active carboxylesterases, however, CES1P1 does not play direct roles in drug metabolism, disease states, or serve as a molecular target for pharmacological agents. No drugs, disease implications, biomarker roles, or specific safety concerns are currently associated with CES1P1, reflecting its lack of protein product and biological activity[3]. Key point: CES1P1 is best understood as a non-functional pseudogene associated with, but distinct from, the drug-metabolizing enzyme carboxylesterase 1, lacking direct biological or therapeutic roles[3].

Other names

Putative inactive carboxylesterase 4CES4PCE-3CESRCES1A3Inactive carboxylesterase 1 pseudogene 1Placental carboxylesterase 3