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Bärenz F, Kschonsak YT, Meyer A, Jafarpour A, Lorenz H, Hoffmann I. Ccdc61 controls centrosomal localization of Cep170 and is required for spindle assembly and symmetry. Mol Biol Cell 2018; 29:3105-3118. [PMID: 30354798 PMCID: PMC6340214 DOI: 10.1091/mbc.e18-02-0115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Microtubule nucleation was uncovered as a key principle of spindle assembly. However, the mechanistic details about microtubule nucleation and the organization of spindle formation and symmetry are currently being revealed. Here we describe the function of coiled-coil domain containing 61 (Ccdc61), a so far uncharacterized centrosomal protein, in spindle assembly and symmetry. Our data describe that Ccdc61 is required for spindle assembly and precise chromosome alignments in mitosis. Microtubule tip-tracking experiments in the absence of Ccdc61 reveal a clear loss of the intrinsic symmetry of microtubule tracks within the spindle. Furthermore, we show that Ccdc61 controls the centrosomal localization of centrosomal protein of 170 kDa (Cep170), a protein that was shown previously to localize to centrosomes as well as spindle microtubules and promotes microtubule organization and microtubule assembly. Interestingly, selective disruption of Ccdc61 impairs the binding between Cep170 and TANK binding kinase 1, an interaction that is required for microtubule stability. In summary, we have discovered Ccdc61 as a centrosomal protein with an important function in mitotic microtubule organization.
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Affiliation(s)
- Felix Bärenz
- Cell Cycle Control and Carcinogenesis, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Yvonne T Kschonsak
- Cell Cycle Control and Carcinogenesis, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Annalena Meyer
- Cell Cycle Control and Carcinogenesis, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Aliakbar Jafarpour
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Holger Lorenz
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Ingrid Hoffmann
- Cell Cycle Control and Carcinogenesis, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
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Antisense Oligonucleotide-Based Splicing Correction in Individuals with Leber Congenital Amaurosis due to Compound Heterozygosity for the c.2991+1655A>G Mutation in CEP290. Int J Mol Sci 2018. [PMID: 29518907 PMCID: PMC5877614 DOI: 10.3390/ijms19030753] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Leber congenital amaurosis (LCA) is a rare inherited retinal disorder affecting approximately 1:50,000 people worldwide. So far, mutations in 25 genes have been associated with LCA, with CEP290 (encoding the Centrosomal protein of 290 kDa) being the most frequently mutated gene. The most recurrent LCA-causing CEP290 mutation, c.2991+1655A>G, causes the insertion of a pseudoexon into a variable proportion of CEP290 transcripts. We previously demonstrated that antisense oligonucleotides (AONs) have a high therapeutic potential for patients homozygously harbouring this mutation, although to date, it is unclear whether rescuing one single allele is enough to restore CEP290 function. Here, we assessed the AON efficacy at RNA, protein and cellular levels in samples that are compound heterozygous for this mutation, together with a protein-truncating mutation in CEP290. We demonstrate that AONs can efficiently restore splicing and increase protein levels. However, due to a high variability in ciliation among the patient-derived cell lines, the efficacy of the AONs was more difficult to assess at the cellular level. This observation points towards the importance of the severity of the second allele and possibly other genetic variants present in each individual. Overall, AONs seem to be a promising tool to treat CEP290-associated LCA, not only in homozygous but also in compound heterozygous carriers of the c.2991+1655A>G variant.
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Canovas Nunes S, Manzoni M, Pizzi M, Mandato E, Carrino M, Quotti Tubi L, Zambello R, Adami F, Visentin A, Barilà G, Trentin L, Manni S, Neri A, Semenzato G, Piazza F. The small GTPase RhoU lays downstream of JAK/STAT signaling and mediates cell migration in multiple myeloma. Blood Cancer J 2018; 8:20. [PMID: 29440639 PMCID: PMC5811530 DOI: 10.1038/s41408-018-0053-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/19/2017] [Accepted: 01/08/2018] [Indexed: 12/22/2022] Open
Abstract
Multiple myeloma is a post-germinal center B-cell neoplasm, characterized by the proliferation of malignant bone marrow plasma cells, whose survival and proliferation is sustained by growth factors and cytokines present in the bone marrow microenvironment. Among them, IL-6 triggers the signal downstream of its receptor, leading to the activation of the JAK/STAT pathway. The atypical GTPase RhoU lays downstream of STAT3 transcription factor and could be responsible for mediating its effects on cytoskeleton dynamics. Here we demonstrate that RHOU is heterogeneously expressed in primary multiple myeloma cells and significantly modulated with disease progression. At the mRNA level, RHOU expression in myeloma patients correlated with the expression of STAT3 and its targets MIR21 and SOCS3. Also, IL-6 stimulation of human myeloma cell lines up-regulated RHOU through STAT3 activation. On the other hand, RhoU silencing led to a decrease in cell migration with the accumulation of actin stress fibers, together with a decrease in cyclin D2 expression and in cell cycle progression. Furthermore, we found that even though lenalidomide positively regulated RhoU expression leading to higher cell migration rates, it actually led to cell cycle arrest probably through a p21 dependent mechanism. Lenalidomide treatment in combination with RhoU silencing determined a loss of cytoskeletal organization inhibiting cell migration, and a further increase in the percentage of cells in a resting phase. These results unravel a role for RhoU not only in regulating the migratory features of malignant plasma cells, but also in controlling cell cycle progression.
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Affiliation(s)
- Sara Canovas Nunes
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Martina Manzoni
- Hematology Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.,Department of Oncology and Hemato-Oncology, University of Milano, Milano, Italy
| | - Marco Pizzi
- Surgical Pathology and Cytopathology Unit, Department of Medicine - DIMED, University of Padova, Padova, Italy
| | - Elisa Mandato
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Marilena Carrino
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Laura Quotti Tubi
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Renato Zambello
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Fausto Adami
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy
| | - Andrea Visentin
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy
| | - Gregorio Barilà
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy
| | - Livio Trentin
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Sabrina Manni
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Antonino Neri
- Hematology Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.,Department of Oncology and Hemato-Oncology, University of Milano, Milano, Italy
| | - Gianpietro Semenzato
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy.,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy
| | - Francesco Piazza
- Department of Medicine, Division of Hematology, University of Padova, Padova, Italy. .,Laboratory of Normal and Malignant Hematopoiesis, Venetian Institute of Molecular Medicine, Padova, Italy.
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Kwon HJ, Park JE, Song H, Jang CY. DDA3 and Mdp3 modulate Kif2a recruitment onto the mitotic spindle to control minus-end spindle dynamics. J Cell Sci 2016; 129:2719-25. [PMID: 27284004 DOI: 10.1242/jcs.180109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 05/25/2016] [Indexed: 11/20/2022] Open
Abstract
Active turnover of spindle microtubules (MTs) for the formation of a bi-orientated spindle, chromosome congression and proper chromosome segregation is regulated by MT depolymerases such as the kinesin-13 family and the plus-end-tracking proteins (+TIPs). However, the control mechanisms underlying the spindle MT dynamics that are responsible for poleward flux at the minus end of MTs are poorly understood. Here, we show that Mdp3 (also known as MAP7D3) forms a complex with DDA3 (also known as PSRC1) and controls spindle dynamics at the minus end of MTs by inhibiting DDA3-mediated Kif2a recruitment to the spindle. Aberrant Kif2a activity at the minus end of spindle MTs in Mdp3-depleted cells decreased spindle stability and resulted in unaligned chromosomes in metaphase, lagging chromosomes in anaphase, and chromosome bridges in telophase and cytokinesis. Although they play opposing roles in minus-end MT dynamics, acting as an MT destabilizer and an MT stabilizer, respectively, DDA3 and Mdp3 did not affect the localization of each other. Thus, the DDA3 complex orchestrates MT dynamics at the MT minus end by fine-tuning the recruitment of Kif2a to regulate minus-end MT dynamics and poleward MT flux at the mitotic spindle.
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Affiliation(s)
- Hye Jin Kwon
- Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women's University, Seoul 140-742, Republic of Korea
| | - Ji Eun Park
- Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women's University, Seoul 140-742, Republic of Korea
| | - Haiyu Song
- Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women's University, Seoul 140-742, Republic of Korea
| | - Chang-Young Jang
- Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women's University, Seoul 140-742, Republic of Korea
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