RESUMO
Despite the importance of cilia in cell signaling and motility, the molecular mechanisms regulating cilium formation remain incompletely understood. Herein, we characterize enkurin domain-containing protein 1 (ENKD1) as a novel centrosomal protein that mediates the removal of centriolar coiled-coil protein 110 (CP110) from the mother centriole to promote ciliogenesis. We show that Enkd1 knockout mice possess ciliogenesis defects in multiple organs. Super-resolution microscopy reveals that ENKD1 is a stable component of the centrosome throughout the ciliogenesis process. Simultaneous knockdown of ENKD1 and CP110 significantly reverses the ciliogenesis defects induced by ENKD1 depletion. Protein interaction analysis shows that ENKD1 competes with centrosomal protein 97 (CEP97) in binding to CP110. Depletion of ENKD1 enhances the CP110-CEP97 interaction and detains CP110 at the mother centriole. These findings thus identify ENKD1 as a centrosomal protein and uncover a novel mechanism controlling CP110 removal from the mother centriole for the initiation of ciliogenesis.
Assuntos
Centríolos , Proteínas Associadas aos Microtúbulos , Animais , Camundongos , Proteínas de Ligação a Calmodulina/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Centríolos/genética , Centríolos/metabolismo , Centrossomo/metabolismo , Cílios/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Plasma Seminal/metabolismoRESUMO
Diffuse large B cell lymphoma (DLBCL) is a common and aggressive form of B cell lymphoma. Approximately 40% of DLBCL patients are incurable despite modern therapeutic approaches. To explore the molecular mechanisms driving the growth and progression of DLBCL, we analyzed genes with differential expression in DLBCL using the Gene Expression Profiling Interactive Analysis database. Enkurin domain-containing protein 1 (ENKD1), a centrosomal protein-encoding gene, was found to be highly expressed in DLBCL samples compared with normal samples. The phylogenetic analysis revealed that ENKD1 is evolutionarily conserved. Depletion of ENKD1 in cultured DLBCL cells induced apoptosis, suppressed cell proliferation, and blocked cell cycle progression in the G2/M phase. Moreover, ENKD1 expression positively correlates with the expression levels of a number of cellular homeostatic regulators, including Sperm-associated antigen 5, a gene encoding an important mitotic regulator. These findings thus demonstrate a critical function for ENKD1 in regulating the cellular homeostasis and suggest a potential value of targeting ENKD1 for the treatment of DLBCL.
Assuntos
Linfoma Difuso de Grandes Células B , Proteínas dos Microtúbulos , Humanos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica/genética , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Proteínas dos Microtúbulos/metabolismo , Filogenia , Regulação para Cima/genéticaRESUMO
Centrioles and cilia are conserved, microtubule-based structures critical for cell function and development. Their dysfunction causes cancer and developmental disorders. How microtubules are organized into ordered structures by microtubule-associated proteins (MAPs) and tubulin modifications is best understood during mitosis but is largely unexplored for the centrioles and the ciliary axoneme, which are composed of stable microtubules that maintain their length at a steady-state. In particular, we know little about the identity of the centriolar and ciliary MAPs and how they work together during the assembly and maintenance of the cilium and centriole. Here, we identified the Enkurin domain containing 1 (ENKD1) as a component of the centriole wall and the axoneme in mammalian cells and showed that it has extensive proximity interactions with these compartments and MAPs. Using in vitro and cellular assays, we found that ENKD1 is a new MAP that regulates microtubule organization and stability. Consistently, we observed an increase in tubulin polymerization and microtubule stability, as well as disrupted microtubule organization in ENKD1 overexpression. Cells depleted for ENKD1 were defective in ciliary length and content regulation and failed to respond to Hedgehog pathway activation. Together, our results advance our understanding of the functional and regulatory relationship between MAPs and the primary cilium.
Assuntos
Cílios , Proteínas Associadas aos Microtúbulos , Animais , Centríolos/metabolismo , Centrossomo/metabolismo , Cílios/metabolismo , Proteínas Hedgehog/metabolismo , Mamíferos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismoRESUMO
Non-small cell lung cancer (NSCLC) is the most common cause of cancer mortality worldwide. NSCLC has an aggressive phenotype and poor prognosis, and is quite heterogeneous without effective and specific targeted therapies. Therefore, exploring new tumor markers and drug targets for NSCLC is crucial towards individualized treatment. Here, we demonstrate that enkurin domain containing 1 (ENKD1), a protein with unknown structure and function, is significantly downregulated in NSCLC tumor tissues compared with their non-tumor counterparts. We also show that ENKD1 expression is decreased in NSCLC cells compared to normal human lung epithelial cells. EdU incorporation, wound healing, and transwell invasion assays reveal that ENKD1 regulates the proliferation, migration, and invasion of NSCLC cells. Collectively, these results suggest that ENKD1 plays an important role in NSCLC progression and that ENKD1 is a tumor marker and a potential molecular drug target for the treatment of NSCLC patients.