P3h1, also known as prolyl 3-hydroxylase 1, is crucial for collagen posttranslational processing. It forms a ternary complex with CRTAP and PPIB, playing a key role in the proper assembly and function of collagen [1,9]. The hydroxylation of proline residues in collagen by P3h1 is an important step in collagen biosynthesis, and this process is related to the normal development and structure of tissues [3,7].

In zebrafish, knock out of p3h1 led to phenotypes similar to osteogenesis imperfecta (OI) patients, including reduced size, body disproportion, altered mineralization, vertebral body fusions, deformities, and fractures. Intracellularly, collagen type I was overmodified and partially retained, causing enlarged ER cisternae, and in the extracellular matrix, abnormal collagen type I assembled in disorganized fibers [8]. In humans, mutations in P3H1 are associated with autosomal recessive OI type VIII, which can cause severe skeletal fragility, multiple fractures, and dental anomalies [2,3,5,7].

P3H1 may also be involved in tumor-related processes. In bladder urothelial carcinoma, its high expression was associated with poor prognosis, and high-expression samples had higher immune cell infiltration and enhanced sensitivity to several drugs [4]. Pan-cancer analysis showed that high P3H1 expression was significantly associated with low overall survival in multiple types of cancer [6].

In conclusion, P3h1 is essential for collagen processing, and its malfunction is closely related to OI. Additionally, its role in tumor development, as revealed by various research models, indicates its importance in understanding both skeletal and cancer-related diseases. The study of P3h1 knockout models in zebrafish and human genetic studies of P3H1 mutations have provided valuable insights into its functions in normal biological processes and disease conditions.