Component of centriolar satellites contributing to the building of a complex and dynamic network required to regulate cilia/flagellum formation. In proliferating cells, MIB1-mediated ubiquitination induces its sequestration within centriolar satellites, precluding untimely cilia formation initiation. In contrast, during normal and ultraviolet or heat shock cellular stress-induced ciliogenesis, its non-ubiquitinated form is rapidly displaced from centriolar satellites and recruited to centrosome/basal bodies in a microtubule- and p38 MAPK-dependent manner. Acts also as a negative regulator of BBSome ciliary trafficking (By similarity). Plays a role in sperm flagellar formation; may be involved in the regulation of intraflagellar transport (IFT) and/or intramanchette (IMT) trafficking, which are important for axoneme extension and/or cargo delivery to the nascent sperm tail (PubMed:24415959). Required for optimal cell proliferation and cell cycle progression; may play a role in the regulation of genome stability and centriole duplication in non-ciliogenic cells (By similarity). Involved in centriole duplication (PubMed:26297806). Required for CEP152, WDR62 and CEP63 centrosomal localization and promotes the centrosomal localization of CDK2 (By similarity). Essential for maintaining proper centriolar satellite integrity (By similarity). Self-associates (By similarity). Associates with the centriolar satellite BBSome protein complex (PubMed:24550735) Interacts with BBS4; the interaction limits BBS4 availability for association with the BBSome complex, and hence negatively regulates ciliary localization of the BBSome complex. Interacts with MIB1. Interacts with PCM1; the interaction increases in response to ultraviolet light (UV) radiation. Associates with microtubule; association to microtubule is reduced in response to cellular stress, such as UV stimulation, in a process that requires p38 MAP kinase signaling. Interacts with CEP290, DCTN1, MAP1LC3B, PCNT, PCM1 and CEP152 (By similarity). Interacts with 14-3-3 proteins following UV-induced phosphorylation by MAPKAPK2; this inhibits formation of novel centriolar satellites (By similarity). Interacts with SDCCAG8 (By similarity). Interacts with CCDC61 (By similarity). Interacts with PLK4 (By similarity). Ubiquitinated form is sequestered and colocalized with BBS4, CEP290, PCM1 and PCNT at centriolar satellites in proliferating cells. Traffics towards and away from centriolar satellites and centrosome in a microtubule- and dynein-dependent manner in interphase cells. Displaced from centriolar satellites but still remained associated with centrosome in response to cellular stress, such as ultraviolet light (UV) radiation or heat shock, in a process that requires p38 MAPK signaling (By similarity). Colocalized with pericentriolar material protein PCM1 at centriolar satellites. During spermiogenesis, becomes enriched with nephrocystin NPHP1 at the transition zone, a structure at the base of the ciliary axoneme important for regulating traffic into the ciliary compartment. Traffics towards and away from the centrosome/basal bodies and the transition zone of the ciliary axoneme in a microtubule-dependent manner. Localized at the Golgi-derived acrosome and the centrosome-containing head-tail coupling apparatus (HTCA). Localized to the pre-acrosome region of round and elongated spermatids in testis but also present in ovary, brain and adipose tissue. Widely expressed during development, with strong expression in tissues with high levels of cilia-dependent developmental signaling such as the limbs, eyes, somite derivatives and brain. Significant amounts are found in the testis of 16 day old mice, at a late stage of pachytene spermatocytes when meiosis occurs. The level increases thereafter. By 5-azacytidine. Ubiquitinated. Undergoes monoubiquitination catalyzed by the E3 ubiquitin-protein ligase MIB1 in proliferating cells, preventing cilia formation. Monoubiquitination by MIB1 is inhibited in response to cellular stress, such as ultraviolet light (UV) radiation or heat shock, resulting in ciliogenesis restoration (By similarity). MAPKAPK2-dependent phosphorylation at Ser-47 and Ser-78 occurs in response to cellular stress such as exposure to ultraviolet irradiation and promotes binding to 14-3-3 proteins which leads to cytoplasmic sequestration of CEP131 and blocks formation of new centriolar satellites (By similarity). Phosphorylation at Ser-78 mediated by PLK4 is essential for proper organization and integrity of centriolar satellites but is dispensable for its localization to centrioles and its function in ciliogenesis (By similarity). Females grow normally and are healthy. Males display developing sperm flagella abnormalities resulting in infertility. Post-meiotic defects during spermatogenesis with abnormal morphology of elongating and elongated spermatids, including teratozoospermia, premature apoptosis, but without increase in DNA damage. Sperm are immotile with shortened and morphologically abnormal flagella, and altered intraflagellar transport (IFT) and/or intramanchette (IMT) trafficking. Displays normal postnatal multiciliated airway epithelium. Lacks retinal degeneration and kidney cysts formations. Transient cell cultured-based knock-down (by RNAi) of CEP131 leads to a reduction in ciliogenesis (PubMed:24415959). However, chronic absence of CEP131 following genetic deletion (knockout) shows that cilia develop and function normally in vivo. This suggests that CEP131 is not essential for ciliogenesis, except for the modified cilia of the developing sperm flagella, and that there is an alternative mechanism to compensate for the lack of CEP131 (PubMed:24415959). Belongs to the CEP131 family.