CEP89, also known as centrosomal protein 89, is essential for ciliogenesis, mitochondrial metabolism, and neuronal function. It is involved in pathways related to the formation of primary cilia, which are crucial for cell signaling, and in mitochondrial oxidative phosphorylation. Its function is evolutionarily conserved, making genetic models valuable for its study [2].

In Drosophila, ubiquitous knockdown of fly Cep89 decreased complex IV activity in mitochondria and led to lethality. It was also required for mitochondrial integrity, membrane depolarization, synaptic transmission in photoreceptor neurons, and (sub)synaptic organization at the larval neuromuscular junction, as well as for learning in the light-off jump reflex habituation assay [2]. In ovarian cancer, more than a quarter of patients had copy number gains in the CEP89 gene. High CEP89 expression predicted a more than one-year shorter overall survival compared to low expression, suggesting it could be a prognostic marker and therapeutic target [1]. In ciliogenesis, CEP89 selectively functions in RAB34+ ciliary vesicle recruitment. In mutant cells, the kinetics of ciliary disassembly is significantly delayed [3,4].

In conclusion, CEP89 plays essential roles in mitochondrial metabolism, especially complex IV activity, and in neuronal function. Its study in genetic models has provided insights into its role in ovarian cancer prognosis and ciliary dynamics, highlighting its potential as a therapeutic target in ovarian cancer and its importance in understanding ciliary-related biological processes.

References:

1. Berkel, Caglar, Cacan, Ercan. 2022. Copy number and expression of CEP89, a protein required for ciliogenesis, are increased and predict poor prognosis in patients with ovarian cancer. In Cell biochemistry and function, 40, 298-309. doi:10.1002/cbf.3694. https://pubmed.ncbi.nlm.nih.gov/35285957/

2. van Bon, Bregje W M, Oortveld, Merel A W, Nijtmans, Leo G, de Vries, Bert B A, Schenck, Annette. 2013. CEP89 is required for mitochondrial metabolism and neuronal function in man and fly. In Human molecular genetics, 22, 3138-51. doi:10.1093/hmg/ddt170. https://pubmed.ncbi.nlm.nih.gov/23575228/

3. Kanie, Tomoharu, Love, Julia F, Fisher, Saxton D, Gustavsson, Anna-Karin, Jackson, Peter K. 2023. A hierarchical pathway for assembly of the distal appendages that organize primary cilia. In bioRxiv : the preprint server for biology, , . doi:10.1101/2023.01.06.522944. https://pubmed.ncbi.nlm.nih.gov/36711481/

4. Je, Su-Yeon, Ko, Hyuk Wan. 2024. Distinct roles of centriole distal appendage proteins in ciliary assembly and disassembly. In Cell communication and signaling : CCS, 22, 607. doi:10.1186/s12964-024-01962-7. https://pubmed.ncbi.nlm.nih.gov/39696441/