Polycystic kidney and hepatic disease 1-like protein 1 (PKHD1L1)

Polycystic kidney and hepatic disease 1-like protein 1 (PKHD1L1) is a large transmembrane protein characterized by the presence of multiple Ig-like plexin transcription factor (IPT) domains and G8 domains in its extracellular region[2][4]. PKHD1L1 is highly expressed in the stereocilia of inner ear hair cells, especially at the tips of the stereocilia in the cochlea, where it forms a critical component of the electron-dense surface coat essential for normal hearing[2][4]. In mice and zebrafish, loss of PKHD1L1 leads to the absence of this coat, progressive sensorineural hearing loss, and structural abnormalities in cochlear stereocilia, confirming its essential role in auditory function[2][4]. While structurally related to the PKHD1/fibrocystin-polyductin family involved in polycystic kidney disease, PKHD1L1's primary known function is in the inner ear rather than in renal or hepatic tissue. Unlike PKHD1, there is currently no evidence that PKHD1L1 is a major or direct therapeutic target, nor is there evidence of interacting drugs, established mechanisms of action, or use as a clinical biomarker[2][4][6]. The protein's molecular features suggest it may function similarly to certain cell surface receptors or adhesion molecules but its detailed signaling function remains uncharacterized[2][4]. If more specific structured data about drugs, mechanisms, or safety information are published in the future, they may update its clinical relevance. For now, the principal human disease link is autosomal recessive nonsyndromic deafness (DFNB124) through variants in PKHD1L1[4].

Other names

Fibrocystin-LPKHD1L1PKHD1-like protein 1Polycystic kidney and hepatic disease 1-like protein 1DFNB124PKHDL1polycystic kidney and hepatic disease-like 1