Peroxisomal biogenesis factor 5-like protein (PEX5L)

Peroxisomal biogenesis factor 5-like protein (PEX5L) is a member of the peroxin (PEX) family, which are proteins essential for assembly and maintenance of peroxisomes in eukaryotic cells[1][3]. While canonical PEX5 is established as the receptor for proteins containing peroxisomal targeting signal 1 (PTS1), necessary for their import into the peroxisomal matrix, the "peroxisomal biogenesis factor 5-like" (PEX5L) nomenclature actually denotes a related gene distinct from PEX5 itself. In mammals, PEX5L/TRIP8b is better known as the tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b), which acts as an auxiliary subunit regulating HCN channel trafficking and function in neurons, playing no direct role in peroxisome biogenesis[1]. PEX5L/TRIP8b modulates neuronal excitability by controlling the surface expression and gating of HCN channels (hyperpolarization-activated cyclic nucleotide-gated channels). Though its gene structure resembles that of peroxins, it is not considered a canonical peroxisomal import receptor, nor is it known as a therapeutic drug target or receptor in the classical sense[1][4]. PX5L is frequently misattributed as a peroxisome biogenesis factor or direct drug target, but in current human nomenclature TRIP8b/PEX5L primarily regulates HCN channel function in the nervous system and is not a recognized therapeutic target or biomarker. Some genetic studies report associations between PEX5L variants and Alzheimer's disease risk, but no drug interactions, mechanisms of action, or safety concerns are documented[4]. Note: The search results and literature indicate confusion between PEX5 (the established peroxisome receptor) and PEX5L/PEX5R/TRIP8b (an unrelated neuronal regulatory protein), hence the entry is marked "is_incorrect: true" for purposes where only validated molecular targets (enzymes, receptors, ion channels, etc.) are considered. If you require information about PEX5 (canonical peroxisomal import receptor), please specify; otherwise, "PEX5L" predominantly refers to TRIP8b in current molecular biology, not a therapeutic target[1][4].

Other names

PEX5-related proteinPEX5LPEX5RPXR2Pex5RpTRIP8bPEX2-related proteinPEX5-like proteinPeroxin-5-related proteinPeroxisome biogenesis factor 5-likeTetratricopeptide repeat-containing Rab8b-interacting proteinHCN channel auxiliary subunitPEX5RPPXR2BPex5p-related protein