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Laporte MH, Bouhlel IB, Bertiaux E, Morrison CG, Giroud A, Borgers S, Azimzadeh J, Bornens M, Guichard P, Paoletti A, Hamel V. Human SFI1 and Centrin form a complex critical for centriole architecture and ciliogenesis. EMBO J 2022; 41:e112107. [PMID: 36125182 DOI: 10.15252/embj.2022112107] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/23/2022] [Accepted: 09/02/2022] [Indexed: 11/09/2022] Open
Abstract
Over the course of evolution, the centrosome function has been conserved in most eukaryotes, but its core architecture has evolved differently in some clades, with the presence of centrioles in humans and a spindle pole body (SPB) in yeast. Similarly, the composition of these two core elements has diverged, with the exception of Centrin and SFI1, which form a complex in yeast to initiate SPB duplication. However, it remains unclear whether this complex exists at centrioles and whether its function has been conserved. Here, using expansion microscopy, we demonstrate that human SFI1 is a centriolar protein that associates with a pool of Centrin at the distal end of the centriole. We also find that both proteins are recruited early during procentriole assembly and that depletion of SFI1 results in the loss of the distal pool of Centrin, without altering centriole duplication. Instead, we show that SFI1/Centrin complex is essential for centriolar architecture, CEP164 distribution, and CP110 removal during ciliogenesis. Together, our work reveals a conserved SFI1/Centrin module displaying divergent functions between mammals and yeast.
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Affiliation(s)
- Marine H Laporte
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Imène B Bouhlel
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Eloïse Bertiaux
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Ciaran G Morrison
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.,Centre for Chromosome Biology, School of Biological and Chemical Sciences, National University of Ireland Galway, Galway, Ireland
| | - Alexia Giroud
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Susanne Borgers
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | | | - Michel Bornens
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Anne Paoletti
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
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2
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Structural Basis for the Functional Diversity of Centrins: A Focus on Calcium Sensing Properties and Target Recognition. Int J Mol Sci 2021; 22:ijms222212173. [PMID: 34830049 PMCID: PMC8622359 DOI: 10.3390/ijms222212173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 11/23/2022] Open
Abstract
Centrins are a family of small, EF hand-containing proteins that are found in all eukaryotes and are often complexed with centrosome-related structures. Since their discovery, centrins have attracted increasing interest due to their multiple, diverse cellular functions. Centrins are similar to calmodulin (CaM) in size, structure and domain organization, although in contrast to CaM, the majority of centrins possess at least one calcium (Ca2+) binding site that is non-functional, thus displaying large variance in Ca2+ sensing abilities that could support their functional versatility. In this review, we summarize current knowledge on centrins from both biophysical and structural perspectives with an emphasis on centrin-target interactions. In-depth analysis of the Ca2+ sensing properties of centrins and structures of centrins complexed with target proteins can provide useful insight into the mechanisms of the different functions of centrins and how these proteins contribute to the complexity of the Ca2+ signaling cascade. Moreover, it can help to better understand the functional redundancy of centrin isoforms and centrin-binding proteins.
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3
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Chen J, Xiong Z, Miller DE, Yu Z, McCroskey S, Bradford WD, Cavanaugh AM, Jaspersen SL. The role of gene dosage in budding yeast centrosome scaling and spontaneous diploidization. PLoS Genet 2020; 16:e1008911. [PMID: 33332348 PMCID: PMC7775121 DOI: 10.1371/journal.pgen.1008911] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 12/31/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022] Open
Abstract
Ploidy is the number of whole sets of chromosomes in a species. Ploidy is typically a stable cellular feature that is critical for survival. Polyploidization is a route recognized to increase gene dosage, improve fitness under stressful conditions and promote evolutionary diversity. However, the mechanism of regulation and maintenance of ploidy is not well characterized. Here, we examine the spontaneous diploidization associated with mutations in components of the Saccharomyces cerevisiae centrosome, known as the spindle pole body (SPB). Although SPB mutants are associated with defects in spindle formation, we show that two copies of the mutant in a haploid yeast favors diploidization in some cases, leading us to speculate that the increased gene dosage in diploids ‘rescues’ SPB duplication defects, allowing cells to successfully propagate with a stable diploid karyotype. This copy number-based rescue is linked to SPB scaling: certain SPB subcomplexes do not scale or only minimally scale with ploidy. We hypothesize that lesions in structures with incompatible allometries such as the centrosome may drive changes such as whole genome duplication, which have shaped the evolutionary landscape of many eukaryotes. Ploidy is the number of whole sets of chromosomes in a species. Most eukaryotes alternate between a diploid (two copy) and haploid (one copy) state during their life and sexual cycle. However, as part of normal human development, specific tissues increase their DNA content. This gain of entire sets of chromosomes is known as polyploidization, and it is observed in invertebrates, plants and fungi, as well. Polyploidy is thought to improve fitness under stressful conditions and promote evolutionary diversity, but how ploidy is determined is poorly understood. Here, we use budding yeast to investigate mechanisms underlying the ploidy of wild-type cells and specific mutants that affect the centrosome, a conserved structure involved in chromosome segregation during cell division. Our work suggests that different scaling relationships (allometry) between the genome and cellular structures underlies alterations in ploidy. Furthermore, mutations in cellular structures with incompatible allometric relationships with the genome may drive genomic changes such duplications, which are underly the evolution of many species including both yeasts and humans.
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Affiliation(s)
- Jingjing Chen
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Zhiyong Xiong
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Danny E. Miller
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Scott McCroskey
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - William D. Bradford
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Ann M. Cavanaugh
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Sue L. Jaspersen
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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4
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Konuk HB, Ergüden B. Spindle pole body duplication defective yeast cells are more prone to membrane damage. Mycologia 2019; 111:895-903. [DOI: 10.1080/00275514.2019.1659091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Hatice Büşra Konuk
- Department of Bioengineering, Gebze Technical University, Gebze 41400, Kocaeli, Turkey
| | - Bengü Ergüden
- Department of Bioengineering, Gebze Technical University, Gebze 41400, Kocaeli, Turkey
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5
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Khouj EM, Prosser SL, Tada H, Chong WM, Liao JC, Sugasawa K, Morrison CG. Differential requirements for the EF-hand domains of human centrin 2 in primary ciliogenesis and nucleotide excision repair. J Cell Sci 2019; 132:jcs.228486. [PMID: 31492759 DOI: 10.1242/jcs.228486] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 08/29/2019] [Indexed: 12/16/2022] Open
Abstract
Centrin 2 is a small conserved calcium-binding protein that localizes to the centriolar distal lumen in human cells. It is required for efficient primary ciliogenesis and nucleotide excision repair (NER). Centrin 2 forms part of the xeroderma pigmentosum group C protein complex. To explore how centrin 2 contributes to these distinct processes, we mutated the four calcium-binding EF-hand domains of human centrin 2. Centrin 2 in which all four EF-hands had been mutated to ablate calcium binding (4DA mutant) was capable of supporting in vitro NER and was as effective as the wild-type protein in rescuing the UV sensitivity of centrin 2-null cells. However, we found that mutation of any of the EF-hand domains impaired primary ciliogenesis in human TERT-RPE1 cells to the same extent as deletion of centrin 2. Phenotypic analysis of the 4DA mutant revealed defects in centrosome localization, centriole satellite assembly, ciliary assembly and function and in interactions with POC5 and SFI1. These observations indicate that centrin 2 requires calcium-binding capacity for its primary ciliogenesis functions, but not for NER, and suggest that these functions require centrin 2 to be capable of forming complexes with partner proteins.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ebtissal M Khouj
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway H91 W2TY, Ireland
| | - Suzanna L Prosser
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway H91 W2TY, Ireland.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada
| | - Haruto Tada
- Biosignal Research Center, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.,Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Weng Man Chong
- IAMS Academia Sinica, No 1 Roosevelt Rd Sec 4, 10617 Taipei City, Taiwan
| | - Jung-Chi Liao
- IAMS Academia Sinica, No 1 Roosevelt Rd Sec 4, 10617 Taipei City, Taiwan
| | - Kaoru Sugasawa
- Biosignal Research Center, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.,Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan
| | - Ciaran G Morrison
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway H91 W2TY, Ireland
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6
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Calcium and phosphorylation double-regulating caltractin initiating target protein XPC function. Int J Biol Macromol 2019; 136:503-511. [DOI: 10.1016/j.ijbiomac.2019.06.095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 01/22/2023]
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7
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Weill U, Cohen N, Fadel A, Ben-Dor S, Schuldiner M. Protein Topology Prediction Algorithms Systematically Investigated in the Yeast Saccharomyces cerevisiae. Bioessays 2019; 41:e1800252. [PMID: 31297843 DOI: 10.1002/bies.201800252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 05/05/2019] [Indexed: 11/09/2022]
Abstract
Membrane proteins perform a variety of functions, all crucially dependent on their orientation in the membrane. However, neither the exact number of transmembrane domains (TMDs) nor the topology of most proteins have been experimentally determined. Due to this, most scientists rely primarily on prediction algorithms to determine topology and TMD assignments. Since these can give contradictory results, single-algorithm-based predictions are unreliable. To map the extent of potential misanalysis, the predictions of nine algorithms on the yeast proteome are compared and it is found that they have little agreement when predicting TMD number and termini orientation. To view all predictions in parallel, a webpage called TopologYeast: http://www.weizmann.ac.il/molgen/TopologYeast was created. Each algorithm is compared with experimental data and a poor agreement is found. The analysis suggests that more systematic data on protein topology are required to increase the training sets for prediction algorithms and to have accurate knowledge of membrane protein topology.
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Affiliation(s)
- Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Nir Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Amir Fadel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shifra Ben-Dor
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
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8
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Solution structure of TbCentrin4 from Trypanosoma brucei and its interactions with Ca 2+ and other centrins. Biochem J 2018; 475:3763-3778. [PMID: 30389845 DOI: 10.1042/bcj20180752] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/30/2018] [Accepted: 11/01/2018] [Indexed: 12/17/2022]
Abstract
Centrin is a conserved calcium-binding protein that plays an important role in diverse cellular biological processes such as ciliogenesis, gene expression, DNA repair and signal transduction. In Trypanosoma brucei, TbCentrin4 is mainly localized in basal bodies and bi-lobe structure, and is involved in the processes coordinating karyokinesis and cytokinesis. In the present study, we solved the solution structure of TbCentrin4 using NMR (nuclear magnetic resonance) spectroscopy. TbCentrin4 contains four EF-hand motifs consisting of eight α-helices. Isothermal titration calorimetry experiment showed that TbCentrin4 has a strong Ca2+ binding ability. NMR chemical shift perturbation indicated that TbCentrin4 binds to Ca2+ through its C-terminal domain composed of EF-hand 3 and 4. Meanwhile, we revealed that TbCentrin4 undergoes a conformational change and self-assembly induced by high concentration of Ca2+ Intriguingly, localization of TbCentrin4 was dispersed or disappeared from basal bodies and the bi-lobe structure when the cells were treated with Ca2+ in vivo, implying the influence of Ca2+ on the cellular functions of TbCentrin4. Besides, we observed the interactions between TbCentrin4 and other Tbcentrins and revealed that the interactions are Ca2+ dependent. Our findings provide a structural basis for better understanding the biological functions of TbCentrin4 in the relevant cellular processes.
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9
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Ergüden B. Dhh1 is a member of the SESA network. Yeast 2018; 36:99-105. [PMID: 30346046 DOI: 10.1002/yea.3363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 10/10/2018] [Accepted: 10/16/2018] [Indexed: 11/09/2022] Open
Abstract
The correct separation of chromosomes during mitosis is necessary to prevent genetic instability and aneuploidy, which are responsible for cancer and other diseases, and it depends on proper centrosome duplication. In a recent study, we found that Smy2 can suppress the essential role of Mps2 in the insertion of yeast centrosome into the nuclear membrane by interacting with Eap1, Scp160, and Asc1 and designated this network as SESA (Smy2, Eap1, Scp160, Asc1). Detailed analysis showed that the SESA network is part of a mechanism which regulates translation of POM34 mRNA. Thus, SESA is a system that suppresses spindle pole body duplication defects by repressing the translation of POM34 mRNA. In this study, we performed a genome-wide screening in order to identify new members of the SESA network and confirmed Dhh1 as a putative member. Dhh1 is a cytoplasmic DEAD-box helicase known to regulate translation. Therefore, we hypothesized that Dhh1 is responsible for the highly selective inhibition of POM34 mRNA by SESA.
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Affiliation(s)
- Bengü Ergüden
- Department of Bioengineering, Gebze Technical University, Kocaeli, Turkey
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10
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Agarwal M, Jin H, McClain M, Fan J, Koch BA, Jaspersen SL, Yu HG. The half-bridge component Kar1 promotes centrosome separation and duplication during budding yeast meiosis. Mol Biol Cell 2018; 29:1798-1810. [PMID: 29847244 PMCID: PMC6085829 DOI: 10.1091/mbc.e18-03-0163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 12/02/2022] Open
Abstract
The budding yeast centrosome, often called the spindle pole body (SPB), nucleates microtubules for chromosome segregation during cell division. An appendage, called the half bridge, attaches to one side of the SPB and regulates SPB duplication and separation. Like DNA, the SPB is duplicated only once per cell cycle. During meiosis, however, after one round of DNA replication, two rounds of SPB duplication and separation are coupled with homologue segregation in meiosis I and sister-chromatid segregation in meiosis II. How SPB duplication and separation are regulated during meiosis remains to be elucidated, and whether regulation in meiosis differs from that in mitosis is unclear. Here we show that overproduction of the half-bridge component Kar1 leads to premature SPB separation during meiosis. Furthermore, excessive Kar1 induces SPB overduplication to form supernumerary SPBs, leading to chromosome missegregation and erroneous ascospore formation. Kar1--mediated SPB duplication bypasses the requirement of dephosphorylation of Sfi1, another half-bridge component previously identified as a licensing factor. Our results therefore reveal an unexpected role of Kar1 in licensing meiotic SPB duplication and suggest a unique mechanism of SPB regulation during budding yeast meiosis.
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Affiliation(s)
- Meenakshi Agarwal
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Hui Jin
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | | | - Jinbo Fan
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Bailey A. Koch
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Sue L. Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Hong-Guo Yu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
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11
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Delayed Encounter of Parental Genomes Can Lead to Aneuploidy in Saccharomyces cerevisiae. Genetics 2017; 208:139-151. [PMID: 29150427 DOI: 10.1534/genetics.117.300289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 10/31/2017] [Indexed: 11/18/2022] Open
Abstract
We have investigated an extreme deviation from the norm of genome unification that occurs during mating in the yeast, Saccharomyces cerevisiae This deviation is encountered when yeast that carry a mutation of the spindle pole body protein, Kar1, are mated with wildtype cells. In this case, nuclear fusion is delayed and the genotypes of a fraction of zygotic progeny suggest that chromosomes have "transferred" between the parental nuclei in zygotes. This classic, yet bizarre, occurrence is routinely used to generate aneuploid (disomic) yeast. [kar1 × wt] zygotes, like [wt × wt] zygotes, initially have a single spindle pole body per nucleus. Unlike [wt × wt] zygotes, in [kar1 × wt] zygotes, the number of spindle pole bodies per nucleus then can increase before nuclear fusion. When such nuclei fuse, the spindle pole bodies do not coalesce efficiently, and subsets of spindle pole bodies and centromeres can enter buds. The genotypes of corresponding biparental progeny show evidence of extensive haplotype-biased chromosome loss, and can also include heterotypic chromosomal markers. They thus allow rationalization of chromosome "transfer" as being due to an unanticipated yet plausible mechanism. Perturbation of the unification of genomes likely contributes to infertility in other organisms.
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12
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Kim SY, Kim DS, Hong JE, Park JH. Crystal structure of wild-type centrin 1 from Mus musculus occupied by Ca2+. BIOCHEMISTRY (MOSCOW) 2017; 82:1129-1139. [DOI: 10.1134/s0006297917100054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Maekawa H, Neuner A, Rüthnick D, Schiebel E, Pereira G, Kaneko Y. Polo-like kinase Cdc5 regulates Spc72 recruitment to spindle pole body in the methylotrophic yeast Ogataea polymorpha. eLife 2017; 6:24340. [PMID: 28853395 PMCID: PMC5626484 DOI: 10.7554/elife.24340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 08/17/2017] [Indexed: 11/17/2022] Open
Abstract
Cytoplasmic microtubules (cMT) control mitotic spindle positioning in many organisms, and are therefore pivotal for successful cell division. Despite its importance, the temporal control of cMT formation remains poorly understood. Here we show that unlike the best-studied yeast Saccharomyces cerevisiae, position of pre-anaphase nucleus is not strongly biased toward bud neck in Ogataea polymorpha and the regulation of spindle positioning becomes active only shortly before anaphase. This is likely due to the unstable property of cMTs compared to those in S. cerevisiae. Furthermore, we show that cMT nucleation/anchoring is restricted at the level of recruitment of the γ-tubulin complex receptor, Spc72, to spindle pole body (SPB), which is regulated by the polo-like kinase Cdc5. Additionally, electron microscopy revealed that the cytoplasmic side of SPB is structurally different between G1 and anaphase. Thus, polo-like kinase dependent recruitment of γ-tubulin receptor to SPBs determines the timing of spindle orientation in O. polymorpha. Before a cell divides, it needs to duplicate its genetic material to provide the new daughter cell with a full set of genetic information. To do so, the cell forms a complex of proteins called the spindle apparatus, which is made up of string-like microtubules that divide the chromosomes evenly. In many organisms, the position of the spindle determines where in the cell this separation happens. However, in baker’s yeast, the location where the cell will divide is determined well before the spindle is formed. Unlike many other eukaryotic cells, these yeast cells divide asymmetrically and create buds that will form the new daughter cells. The position of this bud determines where the spindle should be located and where the chromosomes separate. The spindle itself is then organised by a structure called the spindle pole body, which connects to microtubules inside the cell nucleus and microtubules in the cell plasma. Several proteins control where and how the spindle forms, including a protein called the spindle pole component 72, or Spc72 for short, and an enzyme called Cdc5. However, until now it was unclear how spindle formation is timed and controlled in other yeast species. Now, Maekawa et al. have used fluorescent markers and time lapse microscopy to examine how the spindle forms in the yeast species Ogataea polymorpha, an important industrial yeast used to produce medicines and alcohol. The results show that in O. polymorpha, the positioning and orientation of the spindle only occurred very late in the cell cycle and the microtubules in the cell plasma remained unstable until the chromosomes were about to separate. This was linked to changes in the level of Spc72, which increased at the spindle pole body before the chromosomes separated and then dropped again. This was controlled by Cdc5. Understanding when and where microtubules are formed is an important step in understanding how cells divide. This is the first example of a budding yeast that creates new microtubules in the cell plasma every time the cell divides. Unravelling the molecular differences between yeast species could lead to new ways to optimise the use of industrial yeasts like O. polymorpha, or to combat disease-causing ones.
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Affiliation(s)
- Hiromi Maekawa
- Graduate School of Engineering, Osaka University, Suita, Japan.,Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Annett Neuner
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Diana Rüthnick
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Gislene Pereira
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany.,Division of Centrosomes and Cilia, German Cancer Research Centre (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
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14
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Fox C, Zou J, Rappsilber J, Marston AL. Cdc14 phosphatase directs centrosome re-duplication at the meiosis I to meiosis II transition in budding yeast. Wellcome Open Res 2017. [DOI: 10.12688/wellcomeopenres.10507.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BackgroundGametes are generated through a specialized cell division called meiosis, in which ploidy is reduced by half because two consecutive rounds of chromosome segregation, meiosis I and meiosis II, occur without intervening DNA replication. This contrasts with the mitotic cell cycle where DNA replication and chromosome segregation alternate to maintain the same ploidy. At the end of mitosis, CDKs are inactivated. This low CDK state in late mitosis/G1 allows for critical preparatory events for DNA replication and centrosome/spindle pole body (SPB) duplication. However, their execution is inhibited until S phase, where further preparatory events are also prevented. This “licensing” ensures that both the chromosomes and the centrosomes/SPBs replicate exactly once per cell cycle, thereby maintaining constant ploidy. Crucially, between meiosis I and meiosis II, centrosomes/SPBs must be re-licensed, but DNA re-replication must be avoided. In budding yeast, the Cdc14 protein phosphatase triggers CDK down regulation to promote exit from mitosis. Cdc14 also regulates the meiosis I to meiosis II transition, though its mode of action has remained unclear.MethodsFluorescence and electron microscopy was combined with proteomics to probe SPB duplication in cells with inactive or hyperactive Cdc14.ResultsWe demonstrate that Cdc14 ensures two successive nuclear divisions by re-licensing SPBs at the meiosis I to meiosis II transition. We show that Cdc14 is asymmetrically enriched on a single SPB during anaphase I and provide evidence that this enrichment promotes SPB re-duplication. Cells with impaired Cdc14 activity fail to promote extension of the SPB half-bridge, the initial step in morphogenesis of a new SPB. Conversely, cells with hyper-active Cdc14 duplicate SPBs, but fail to induce their separation.ConclusionOur findings implicate reversal of key CDK-dependent phosphorylations in the differential licensing of cyclical events at the meiosis I to meiosis I transition.
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15
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Fox C, Zou J, Rappsilber J, Marston AL. Cdc14 phosphatase directs centrosome re-duplication at the meiosis I to meiosis II transition in budding yeast. Wellcome Open Res 2017; 2:2. [PMID: 28133632 PMCID: PMC5266553 DOI: 10.12688/wellcomeopenres.10507.2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background: Gametes are generated through a specialized cell division called meiosis, in which ploidy is reduced by half because two consecutive rounds of chromosome segregation, meiosis I and meiosis II, occur without intervening DNA replication. This contrasts with the mitotic cell cycle where DNA replication and chromosome segregation alternate to maintain the same ploidy. At the end of mitosis, cyclin-dependent kinases (CDKs) are inactivated. This low CDK state in late mitosis/G1 allows for critical preparatory events for DNA replication and centrosome/spindle pole body (SPB) duplication. However, their execution is inhibited until S phase, where further preparatory events are also prevented. This “licensing” ensures that both the chromosomes and the centrosomes/SPBs replicate exactly once per cell cycle, thereby maintaining constant ploidy. Crucially, between meiosis I and meiosis II, centrosomes/SPBs must be re-licensed, but DNA re-replication must be avoided. In budding yeast, the Cdc14 protein phosphatase triggers CDK down regulation to promote exit from mitosis. Cdc14 also regulates the meiosis I to meiosis II transition, though its mode of action has remained unclear. Methods: Fluorescence and electron microscopy was combined with proteomics to probe SPB duplication in cells with inactive or hyperactive Cdc14. Results: We demonstrate that Cdc14 ensures two successive nuclear divisions by re-licensing SPBs at the meiosis I to meiosis II transition. We show that Cdc14 is asymmetrically enriched on a single SPB during anaphase I and provide evidence that this enrichment promotes SPB re-duplication. Cells with impaired Cdc14 activity fail to promote extension of the SPB half-bridge, the initial step in morphogenesis of a new SPB. Conversely, cells with hyper-active Cdc14 duplicate SPBs, but fail to induce their separation. Conclusion: Our findings implicate reversal of key CDK-dependent phosphorylations in the differential licensing of cyclical events at the meiosis I to meiosis II transition.
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Affiliation(s)
- Colette Fox
- The Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Edinburgh, UK
| | - Juan Zou
- The Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Edinburgh, UK
| | - Juri Rappsilber
- The Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Edinburgh, UK.,Chair of Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Adele L Marston
- The Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, Edinburgh, UK
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16
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Abstract
The yeast spindle pole body (SPB) is the functional equivalent of the mammalian centrosome. Centrosomes and SPBs duplicate exactly once per cell cycle by mechanisms that use the mother structure as a platform for the assembly of the daughter. The conserved Sfi1 and centrin proteins are essential components of the SPB duplication process. Sfi1 is an elongated molecule that has, in its center, 20 to 23 binding sites for the Ca(2+)-binding protein centrin. In the yeastSaccharomyces cerevisiae, all Sfi1 N termini are in contact with the mother SPB whereas the free C termini are distal to it. During S phase and early mitosis, cyclin-dependent kinase 1 (Cdk1) phosphorylation of mainly serine residues in the Sfi1 C termini blocks the initiation of SPB duplication ("off" state). Upon anaphase onset, the phosphatase Cdc14 dephosphorylates Sfi1 ("on" state) to promote antiparallel and shifted incorporation of cytoplasmic Sfi1 molecules into the half-bridge layer, which thereby elongates into the bridge. The Sfi1 C termini of the two Sfi1 layers localize in the bridge center, whereas the N termini of the newly assembled Sfi1 molecules are distal to the mother SPB. These free Sfi1 N termini then assemble the new SPB in G1phase. Recruitment of Sfi1 molecules into the anaphase SPB and bridge formation were also observed inSchizosaccharomyces pombe, suggesting that the Sfi1 bridge cycle is conserved between the two organisms. Thus, restricting SPB duplication to one event per cell cycle requires only an oscillation between Cdk1 kinase and Cdc14 phosphatase activities. This clockwork regulates the "on"/"off" state of the Sfi1-centrin receiver.
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Sec66-Dependent Regulation of Yeast Spindle-Pole Body Duplication Through Pom152. Genetics 2015; 201:1479-95. [PMID: 26510791 PMCID: PMC4676539 DOI: 10.1534/genetics.115.178012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/23/2015] [Indexed: 02/06/2023] Open
Abstract
In closed mitotic systems such as Saccharomyces cerevisiae, the nuclear envelope (NE) does not break down during mitosis, so microtubule-organizing centers such as the spindle-pole body (SPB) must be inserted into the NE to facilitate bipolar spindle formation and chromosome segregation. The mechanism of SPB insertion has been linked to NE insertion of nuclear pore complexes (NPCs) through a series of genetic and physical interactions between NPCs and SPB components. To identify new genes involved in SPB duplication and NE insertion, we carried out genome-wide screens for suppressors of deletion alleles of SPB components, including Mps3 and Mps2. In addition to the nucleoporins POM152 and POM34, we found that elimination of SEC66/SEC71/KAR7 suppressed lethality of cells lacking MPS2 or MPS3. Sec66 is a nonessential subunit of the Sec63 complex that functions together with the Sec61 complex in import of proteins into the endoplasmic reticulum (ER). Cells lacking Sec66 have reduced levels of Pom152 protein but not Pom34 or Ndc1, a shared component of the NPC and SPB. The fact that Sec66 but not other subunits of the ER translocon bypass deletion mutants in SPB genes suggests a specific role for Sec66 in the control of Pom152 levels. Based on the observation that sec66∆ does not affect the distribution of Ndc1 on the NE or Ndc1 binding to the SPB, we propose that Sec66-mediated regulation of Pom152 plays an NPC-independent role in the control of SPB duplication.
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18
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Burns S, Avena JS, Unruh JR, Yu Z, Smith SE, Slaughter BD, Winey M, Jaspersen SL. Structured illumination with particle averaging reveals novel roles for yeast centrosome components during duplication. eLife 2015; 4. [PMID: 26371506 PMCID: PMC4564689 DOI: 10.7554/elife.08586] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/11/2015] [Indexed: 01/23/2023] Open
Abstract
Duplication of the yeast centrosome (called the spindle pole body, SPB) is thought to occur through a series of discrete steps that culminate in insertion of the new SPB into the nuclear envelope (NE). To better understand this process, we developed a novel two-color structured illumination microscopy with single-particle averaging (SPA-SIM) approach to study the localization of all 18 SPB components during duplication using endogenously expressed fluorescent protein derivatives. The increased resolution and quantitative intensity information obtained using this method allowed us to demonstrate that SPB duplication begins by formation of an asymmetric Sfi1 filament at mitotic exit followed by Mps1-dependent assembly of a Spc29- and Spc42-dependent complex at its tip. Our observation that proteins involved in membrane insertion, such as Mps2, Bbp1, and Ndc1, also accumulate at the new SPB early in duplication suggests that SPB assembly and NE insertion are coupled events during SPB formation in wild-type cells. DOI:http://dx.doi.org/10.7554/eLife.08586.001 Cells divide to produce two new daughter cells that each contain the same genetic material. First, the DNA of the parent cell is copied, then it must be physically separated into the daughter cells by a structure made of filaments called microtubules. To ensure that the DNA is separated into two equal parts, the microtubules must emerge from two points in the cell, known as spindle poles. Each spindle pole is made of a group (or ‘complex’) of proteins and these have to be copied before the cell can divide. While we understand how DNA is copied, we do not know how cells copy proteins. The spindle pole in yeast—known as the spindle pole body—is an ideal model to study this problem because the proteins that form it have already been identified and it is easy to study yeast in the laboratory. Burns et al. developed a new method to study the spindle pole body using fluorescent protein tags and a sophisticated microscopy technique. The experiments mapped the positions of 18 proteins within the spindle pole body during its duplication. Some of these proteins enable the spindle pole to insert into the membrane that surrounds the cell's nucleus. Unexpectedly, Burns et al. observed that this set of proteins interact with the new spindle pole as it forms, instead of afterwards as was previously believed. Burns et al.'s findings suggest that the spindle pole body assembles into the membrane surrounding the nucleus at the same time as it is copied. The next challenges are to understand the details of how this works and to use the same method to study other large protein complexes in cells. Until now, highly detailed surveys of protein structures have been limited to a handful of proteins and conditions. The method developed by Burns et al. makes it possible to carry out studies that examine the movements of whole protein complexes during cell division. DOI:http://dx.doi.org/10.7554/eLife.08586.002
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Affiliation(s)
- Shannon Burns
- Stowers Institute for Medical Research, Kansas City, United States
| | - Jennifer S Avena
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, United States
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, United States
| | - Sarah E Smith
- Stowers Institute for Medical Research, Kansas City, United States
| | | | - Mark Winey
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, United States
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19
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Seybold C, Elserafy M, Rüthnick D, Ozboyaci M, Neuner A, Flottmann B, Heilemann M, Wade RC, Schiebel E. Kar1 binding to Sfi1 C-terminal regions anchors the SPB bridge to the nuclear envelope. J Cell Biol 2015; 209:843-61. [PMID: 26076691 PMCID: PMC4477856 DOI: 10.1083/jcb.201412050] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/20/2015] [Indexed: 11/22/2022] Open
Abstract
The yeast spindle pole body (SPB) is the functional equivalent of the mammalian centrosome. The half bridge is a SPB substructure on the nuclear envelope (NE), playing a key role in SPB duplication. Its cytoplasmic components are the membrane-anchored Kar1, the yeast centrin Cdc31, and the Cdc31-binding protein Sfi1. In G1, the half bridge expands into the bridge through Sfi1 C-terminal (Sfi1-CT) dimerization, the licensing step for SPB duplication. We exploited photo-activated localization microscopy (PALM) to show that Kar1 localizes in the bridge center. Binding assays revealed direct interaction between Kar1 and C-terminal Sfi1 fragments. kar1Δ cells whose viability was maintained by the dominant CDC31-16 showed an arched bridge, indicating Kar1's function in tethering Sfi1 to the NE. Cdc31-16 enhanced Cdc31-Cdc31 interactions between Sfi1-Cdc31 layers, as suggested by binding free energy calculations. In our model, Kar1 binding is restricted to Sfi1-CT and Sfi1 C-terminal centrin-binding repeats, and centrin and Kar1 provide cross-links, while Sfi1-CT stabilizes the bridge and ensures timely SPB separation.
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Affiliation(s)
- Christian Seybold
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Menattallah Elserafy
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Diana Rüthnick
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Musa Ozboyaci
- Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany Heidelberg Graduate School of Mathematical and Computational Methods for the Sciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Annett Neuner
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Benjamin Flottmann
- Institute for Anatomy and Cell Biology, Functional Neuroanatomy, Heidelberg University, 69120 Heidelberg, Germany Institute for Physical and Theoretical Chemistry, Johann-Wolfgang-Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Mike Heilemann
- Institute for Anatomy and Cell Biology, Functional Neuroanatomy, Heidelberg University, 69120 Heidelberg, Germany Institute for Physical and Theoretical Chemistry, Johann-Wolfgang-Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Rebecca C Wade
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany Heidelberg Institute for Theoretical Studies, 69118 Heidelberg, Germany Interdisciplinary Center for Scientific Computing, Heidelberg University, 69120 Heidelberg, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
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20
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Li P, Shao Y, Jin H, Yu HG. Ndj1, a telomere-associated protein, regulates centrosome separation in budding yeast meiosis. ACTA ACUST UNITED AC 2015; 209:247-59. [PMID: 25897084 PMCID: PMC4411264 DOI: 10.1083/jcb.201408118] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 03/16/2015] [Indexed: 11/22/2022]
Abstract
A refined spindle pole body (SPB) affinity purification method reveals that the telomere-associated protein Ndj1 also localizes to yeast SPBs, protects them from premature separation, and therefore regulates both SPB cohesion and telomere clustering during meiosis. Yeast centrosomes (called spindle pole bodies [SPBs]) remain cohesive for hours during meiotic G2 when recombination takes place. In contrast, SPBs separate within minutes after duplication in vegetative cells. We report here that Ndj1, a previously known meiosis-specific telomere-associated protein, is required for protecting SPB cohesion. Ndj1 localizes to the SPB but dissociates from it ∼16 min before SPB separation. Without Ndj1, meiotic SPBs lost cohesion prematurely, whereas overproduction of Ndj1 delayed SPB separation. When produced ectopically in vegetative cells, Ndj1 caused SPB separation defects and cell lethality. Localization of Ndj1 to the SPB depended on the SUN domain protein Mps3, and removal of the N terminus of Mps3 allowed SPB separation and suppressed the lethality of NDJ1-expressing vegetative cells. Finally, we show that Ndj1 forms oligomeric complexes with Mps3, and that the Polo-like kinase Cdc5 regulates Ndj1 protein stability and SPB separation. These findings reveal the underlying mechanism that coordinates yeast centrosome dynamics with meiotic telomere movement and cell cycle progression.
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Affiliation(s)
- Ping Li
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Yize Shao
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Hui Jin
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Hong-Guo Yu
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
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21
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Abstract
The centrosome was discovered in the late 19th century when mitosis was first described. Long recognized as a key organelle of the spindle pole, its core component, the centriole, was realized more than 50 or so years later also to comprise the basal body of the cilium. Here, we chart the more recent acquisition of a molecular understanding of centrosome structure and function. The strategies for gaining such knowledge were quickly developed in the yeasts to decipher the structure and function of their distinctive spindle pole bodies. Only within the past decade have studies with model eukaryotes and cultured cells brought a similar degree of sophistication to our understanding of the centrosome duplication cycle and the multiple roles of this organelle and its component parts in cell division and signaling. Now as we begin to understand these functions in the context of development, the way is being opened up for studies of the roles of centrosomes in human disease.
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Affiliation(s)
- Jingyan Fu
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Iain M Hagan
- Cancer Research UK Manchester Institute, University of Manchester, Withington, Manchester M20 4BX, United Kingdom
| | - David M Glover
- Cancer Research UK Cell Cycle Genetics Group, Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
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22
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Lee IJ, Wang N, Hu W, Schott K, Bähler J, Giddings TH, Pringle JR, Du LL, Wu JQ. Regulation of spindle pole body assembly and cytokinesis by the centrin-binding protein Sfi1 in fission yeast. Mol Biol Cell 2014; 25:2735-49. [PMID: 25031431 PMCID: PMC4161509 DOI: 10.1091/mbc.e13-11-0699] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A previous model suggested doubling of Sfi1 as the first step of SPB assembly. Here it is shown that Sfi1 is gradually recruited to SPBs throughout the cell cycle. Conserved tryptophans in Sfi1 are required for its equal partitioning during mitosis, and unequal partitioning of Sfi1 underlies SPB assembly and mitotic defects in the next cell cycle. Centrosomes play critical roles in the cell division cycle and ciliogenesis. Sfi1 is a centrin-binding protein conserved from yeast to humans. Budding yeast Sfi1 is essential for the initiation of spindle pole body (SPB; yeast centrosome) duplication. However, the recruitment and partitioning of Sfi1 to centrosomal structures have never been fully investigated in any organism, and the presumed importance of the conserved tryptophans in the internal repeats of Sfi1 remains untested. Here we report that in fission yeast, instead of doubling abruptly at the initiation of SPB duplication and remaining at a constant level thereafter, Sfi1 is gradually recruited to SPBs throughout the cell cycle. Like an sfi1Δ mutant, a Trp-to-Arg mutant (sfi1-M46) forms monopolar spindles and exhibits mitosis and cytokinesis defects. Sfi1-M46 protein associates preferentially with one of the two daughter SPBs during mitosis, resulting in a failure of new SPB assembly in the SPB receiving insufficient Sfi1. Although all five conserved tryptophans tested are involved in Sfi1 partitioning, the importance of the individual repeats in Sfi1 differs. In summary, our results reveal a link between the conserved tryptophans and Sfi1 partitioning and suggest a revision of the model for SPB assembly.
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Affiliation(s)
- I-Ju Lee
- Graduate Program of Molecular, Cellular, and Developmental Biology, The Ohio State University, Columbus, OH 43210 Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Ning Wang
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Wen Hu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Kersey Schott
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Jürg Bähler
- Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, United Kingdom
| | - Thomas H Giddings
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado-Boulder, Boulder, CO 80309
| | - John R Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing 102206, China
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210
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23
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Elserafy M, Šarić M, Neuner A, Lin TC, Zhang W, Seybold C, Sivashanmugam L, Schiebel E. Molecular Mechanisms that Restrict Yeast Centrosome Duplication to One Event per Cell Cycle. Curr Biol 2014; 24:1456-66. [DOI: 10.1016/j.cub.2014.05.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 05/11/2014] [Accepted: 05/14/2014] [Indexed: 12/29/2022]
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24
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Gibeaux R, Knop M. When yeast cells meet, karyogamy!: an example of nuclear migration slowly resolved. Nucleus 2013; 4:182-8. [PMID: 23715006 DOI: 10.4161/nucl.25021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cytoskeleton-mediated transport processes are central to the subcellular organization of cells. The nucleus constitutes the largest organelle of a cell, and studying how it is positioned and moved around during various types of cell morphogenetic processes has puzzled researchers for a long time. Now, the molecular architectures of the underlying dynamic processes start to reveal their secrets. In yeast, karyogamy denotes the migration of two nuclei toward each other-termed nuclear congression-upon partner cell mating and the subsequent fusion of these nuclei to form a diploid nucleus. It constitutes a well-studied case. Recent insights completed the picture about the molecular processes involved and provided us with a comprehensive model amenable to quantitative computational simulation of the process. This review discusses our understanding of yeast nuclear congression and karyogamy and seeks to explain how a detailed, quantitative and systemic understanding has emerged from this knowledge.
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Affiliation(s)
- Romain Gibeaux
- European Molecular Biology Laboratory EMBL, Heidelberg, Germany
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25
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Gibeaux R, Politi AZ, Nédélec F, Antony C, Knop M. Spindle pole body-anchored Kar3 drives the nucleus along microtubules from another nucleus in preparation for nuclear fusion during yeast karyogamy. Genes Dev 2013; 27:335-49. [PMID: 23388829 DOI: 10.1101/gad.206318.112] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nuclear migration during yeast karyogamy, termed nuclear congression, is required to initiate nuclear fusion. Congression involves a specific regulation of the microtubule minus end-directed kinesin-14 motor Kar3 and a rearrangement of the cytoplasmic microtubule attachment sites at the spindle pole bodies (SPBs). However, how these elements interact to produce the forces necessary for nuclear migration is less clear. We used electron tomography, molecular genetics, quantitative imaging, and first principles modeling to investigate how cytoplasmic microtubules are organized during nuclear congression. We found that Kar3, with the help of its light chain, Cik1, is anchored during mating to the SPB component Spc72 that also serves as a nucleator and anchor for microtubules via their minus ends. Moreover, we show that no direct microtubule-microtubule interactions are required for nuclear migration. Instead, SPB-anchored Kar3 exerts the necessary pulling forces laterally on microtubules emanating from the SPB of the mating partner nucleus. Therefore, a twofold symmetrical application of the core principle that drives nuclear migration in higher cells is used in yeast to drive nuclei toward each other before nuclear fusion.
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Affiliation(s)
- Romain Gibeaux
- European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
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26
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Dantas TJ, Daly OM, Morrison CG. Such small hands: the roles of centrins/caltractins in the centriole and in genome maintenance. Cell Mol Life Sci 2012; 69:2979-97. [PMID: 22460578 PMCID: PMC11114748 DOI: 10.1007/s00018-012-0961-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/20/2012] [Accepted: 03/12/2012] [Indexed: 01/11/2023]
Abstract
Centrins are small, highly conserved members of the EF-hand superfamily of calcium-binding proteins that are found throughout eukaryotes. They play a major role in ensuring the duplication and appropriate functioning of the ciliary basal bodies in ciliated cells. They have also been localised to the centrosome, which is the major microtubule organising centre in animal somatic cells. We describe the identification, cloning and characterisation of centrins in multiple eukaryotic species. Although centrins have been implicated in centriole biogenesis, recent results have indicated that centrosome duplication can, in fact, occur in the absence of centrins. We discuss these data and the non-centrosomal functions that are emerging for the centrins. In particular, we discuss the involvement of centrins in nucleotide excision repair, a process that repairs the DNA lesions that are induced primarily by ultraviolet irradiation. We discuss how centrin may be involved in these diverse processes and contribute to nuclear and cytoplasmic events.
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Affiliation(s)
- Tiago J. Dantas
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland
| | - Owen M. Daly
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland
| | - Ciaran G. Morrison
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, Ireland
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27
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Abstract
The Saccharomyces cerevisiae mitotic spindle in budding yeast is exemplified by its simplicity and elegance. Microtubules are nucleated from a crystalline array of proteins organized in the nuclear envelope, known as the spindle pole body in yeast (analogous to the centrosome in larger eukaryotes). The spindle has two classes of nuclear microtubules: kinetochore microtubules and interpolar microtubules. One kinetochore microtubule attaches to a single centromere on each chromosome, while approximately four interpolar microtubules emanate from each pole and interdigitate with interpolar microtubules from the opposite spindle to provide stability to the bipolar spindle. On the cytoplasmic face, two to three microtubules extend from the spindle pole toward the cell cortex. Processes requiring microtubule function are limited to spindles in mitosis and to spindle orientation and nuclear positioning in the cytoplasm. Microtubule function is regulated in large part via products of the 6 kinesin gene family and the 1 cytoplasmic dynein gene. A single bipolar kinesin (Cin8, class Kin-5), together with a depolymerase (Kip3, class Kin-8) or minus-end-directed kinesin (Kar3, class Kin-14), can support spindle function and cell viability. The remarkable feature of yeast cells is that they can survive with microtubules and genes for just two motor proteins, thus providing an unparalleled system to dissect microtubule and motor function within the spindle machine.
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28
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Zhang Y, He CY. Centrins in unicellular organisms: functional diversity and specialization. PROTOPLASMA 2012; 249:459-467. [PMID: 21786168 DOI: 10.1007/s00709-011-0305-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 07/10/2011] [Indexed: 05/31/2023]
Abstract
Centrins (also known as caltractins) are conserved, EF hand-containing proteins ubiquitously found in eukaryotes. Similar to calmodulins, the calcium-binding EF hands in centrins fold into two structurally similar domains separated by an alpha-helical linker region, shaping like a dumbbell. The small size (15-22 kDa) and domain organization of centrins and their functional diversity/specialization make them an ideal system to study protein structure-function relationship. Here, we review the work on centrins with a focus on their structures and functions characterized in unicellular organisms.
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Affiliation(s)
- Yu Zhang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
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29
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Function of Cryptococcus neoformans KAR7 (SEC66) in karyogamy during unisexual and opposite-sex mating. EUKARYOTIC CELL 2012; 11:783-94. [PMID: 22544906 DOI: 10.1128/ec.00066-12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human basidiomycetous fungal pathogen Cryptococcus neoformans serves as a model fungus to study sexual development and produces infectious propagules, basidiospores, via the sexual cycle. Karyogamy is the process of nuclear fusion and an essential step to complete mating. Therefore, regulation of nuclear fusion is central to understanding sexual development of C. neoformans. However, our knowledge of karyogamy genes was limited. In this study, using a BLAST search with the Saccharomyces cerevisiae KAR genes, we identified five C. neoformans karyogamy gene orthologs: CnKAR2, CnKAR3, CnKAR4, CnKAR7 (or CnSEC66), and CnKAR8. There are no apparent orthologs of the S. cerevisiae genes ScKAR1, ScKAR5, and ScKar9 in C. neoformans. Karyogamy involves the congression of two nuclei followed by nuclear membrane fusion, which results in diploidization. ScKar7 (or ScSec66) is known to be involved in nuclear membrane fusion. In C. neoformans, kar7 mutants display significant defects in hyphal growth and basidiospore chain formation during both a-α opposite and α-α unisexual reproduction. Fluorescent nuclear imaging revealed that during kar7 × kar7 bilateral mutant matings, the nuclei congress but fail to fuse in the basidia. These results demonstrate that the KAR7 gene plays an integral role in both opposite-sex and unisexual mating, indicating that proper control of nuclear dynamics is important. CnKAR2 was found to be essential for viability, and its function in mating is not known. No apparent phenotypes were observed during mating of kar3, kar4, or kar8 mutants, suggesting that the role of these genes may be dispensable for C. neoformans mating, which demonstrates a different evolutionary trajectory for the KAR genes in C. neoformans compared to those in S. cerevisiae.
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Miron S, Durand D, Chilom C, Pérez J, Craescu CT. Binding of calcium, magnesium, and target peptides to Cdc31, the centrin of yeast Saccharomyces cerevisiae. Biochemistry 2011; 50:6409-22. [PMID: 21714500 DOI: 10.1021/bi200518d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cdc31, the Saccharomyces cerevisiae centrin, is an EF-hand calcium-binding protein essential for the cell division and mRNA nuclear export. We used biophysical techniques to investigate its calcium, magnesium, and protein target binding properties as well as their conformations in solution. We show here that Cdc31 displays one Ca(2+)/Mg(2+) mixed site in the N-terminal domain and two low-affinity Ca(2+) sites in the C-terminal domain. The affinity of Cdc31 for different natural target peptides (from Kar1, Sfi1, Sac3) that we obtained by isothermal titration calorimetry shows weakly Ca(2+), but also Mg(2+) dependence. The characteristics of target surface binding were shown to be similar; we highlight that the 1-4 hydrophobic amino acid motif, in a stable amphipathic α-helix, is critical for binding. Ca(2+) and Mg(2+) binding increase the α-helix content and stabilize the structure. Analysis of small-angle X-ray scattering experiments revealed that N- and C-terminal domains are not individualized in apo-Cdc31; in contrast, they are separated in the Mg(2+) state, creating a groove in the middle of the molecule that is occupied by the target peptide in the liganded form. Consequently, Mg(2+) seems to have consequences on Cdc31's function and could be important to stimulate interactions in resting cells.
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Affiliation(s)
- Simona Miron
- Institut Curie Centre de Recherche, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France.
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Buchetics M, Dragosits M, Maurer M, Rebnegger C, Porro D, Sauer M, Gasser B, Mattanovich D. Reverse engineering of protein secretion by uncoupling of cell cycle phases from growth. Biotechnol Bioeng 2011; 108:2403-12. [PMID: 21557199 DOI: 10.1002/bit.23198] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 04/19/2011] [Accepted: 05/02/2011] [Indexed: 12/21/2022]
Abstract
The demand for recombinant proteins both for biopharmaceutical and technical applications is rapidly growing, and therefore the need to establish highly productive expression systems is steadily increasing. Yeasts, such as Pichia pastoris, are among the widely used production platforms with a strong emphasis on secreted proteins. Protein secretion is a limiting factor of productivity. There is strong evidence that secretion is coupled to specific growth rate (µ) in yeast, being higher at higher µ. For maximum productivity and product titer, high specific secretion rates at low µ would be desired. At high secretion rates cultures contain a large fraction of cells in the G2 and M phases of cell cycle. Consequently, the cell design target of a high fraction of cells in G2 + M phase was achieved by constitutive overexpression of the cyclin gene CLB2. Together with predictive process modeling this reverse engineered production strain improved the space time yield (STY) of an antibody Fab fragment by 18% and the product titer by 53%. This concept was verified with another secreted protein, human trypsinogen.
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Affiliation(s)
- Markus Buchetics
- Department of Biotechnology, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria; telephone: +43476546569; fax: +4313697615; Austrian Centre of Industrial Biotechnology (ACIB GmbH),Vienna, Austria
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Changes in the nuclear envelope environment affect spindle pole body duplication in Saccharomyces cerevisiae. Genetics 2010; 186:867-83. [PMID: 20713690 DOI: 10.1534/genetics.110.119149] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Saccharomyces cerevisiae nuclear membrane is part of a complex nuclear envelope environment also containing chromatin, integral and peripheral membrane proteins, and large structures such as nuclear pore complexes (NPCs) and the spindle pole body. To study how properties of the nuclear membrane affect nuclear envelope processes, we altered the nuclear membrane by deleting the SPO7 gene. We found that spo7Δ cells were sickened by the mutation of genes coding for spindle pole body components and that spo7Δ was synthetically lethal with mutations in the SUN domain gene MPS3. Mps3p is required for spindle pole body duplication and for a variety of other nuclear envelope processes. In spo7Δ cells, the spindle pole body defect of mps3 mutants was exacerbated, suggesting that nuclear membrane composition affects spindle pole body function. The synthetic lethality between spo7Δ and mps3 mutants was suppressed by deletion of specific nucleoporin genes. In fact, these gene deletions bypassed the requirement for Mps3p entirely, suggesting that under certain conditions spindle pole body duplication can occur via an Mps3p-independent pathway. These data point to an antagonistic relationship between nuclear pore complexes and the spindle pole body. We propose a model whereby nuclear pore complexes either compete with the spindle pole body for insertion into the nuclear membrane or affect spindle pole body duplication by altering the nuclear envelope environment.
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Araki Y, Gombos L, Migueleti SPS, Sivashanmugam L, Antony C, Schiebel E. N-terminal regions of Mps1 kinase determine functional bifurcation. ACTA ACUST UNITED AC 2010; 189:41-56. [PMID: 20368617 PMCID: PMC2854372 DOI: 10.1083/jcb.200910027] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Spindle pole body components Spc29 and Cdc31 are identified as targets of Mps1 kinase, which, when phosphorylated, regulate protein–protein interactions in the spindle pole body. Mps1 is a conserved kinase that in budding yeast functions in duplication of the spindle pole body (SPB), spindle checkpoint activation, and kinetochore biorientation. The identity of Mps1 targets and the subdomains that convey specificity remain largely unexplored. Using a novel combination of systematic deletion analysis and chemical biology, we identified two regions within the N terminus of Mps1 that are essential for either SPB duplication or kinetochore biorientation. Suppression analysis of the MPS1 mutants defective in SPB duplication and biochemical enrichment of Mps1 identified the essential SPB components Spc29 and the yeast centrin Cdc31 as Mps1 targets in SPB duplication. Our data suggest that phosphorylation of Spc29 by Mps1 in G1/S recruits the Mps2–Bbp1 complex to the newly formed SPB to facilitate its insertion into the nuclear envelope. Mps1 phosphorylation of Cdc31 at the conserved T110 residue controls substrate binding to Kar1 protein. These findings explain the multiple SPB duplication defects of mps1 mutants on a molecular level.
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Affiliation(s)
- Yasuhiro Araki
- Zentrum für Molekulare Biologie der Universität Heidelberg, Deutsches Krebsforschungszentrum-ZMBH Allianz, 69120 Heidelberg, Germany
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Zizlsperger N, Keating AE. Specific coiled-coil interactions contribute to a global model of the structure of the spindle pole body. J Struct Biol 2010; 170:246-56. [PMID: 20139001 DOI: 10.1016/j.jsb.2010.01.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 01/22/2010] [Accepted: 01/23/2010] [Indexed: 11/26/2022]
Abstract
As the microtubule-organizing center of yeast, the spindle pole body (SPB) is essential for cell viability. Structural studies of the SPB are limited by its low copy number in the cell, its large size and heterogeneous composition, and its association with the nuclear membrane. However, low-resolution or indirect structural information about the SPB may be deciphered through a variety of techniques. Interestingly, a large proportion of SPB proteins are predicted to contain one or more coiled coils, a common protein interaction motif. The high frequency of coiled coils suggests that this structure is important for establishing the overall architecture of the complex. Support for this hypothesis was reported previously for coiled coils from some SPB proteins. Here, we extend this approach of isolating and characterizing additional SPB coiled coils to improve our understanding of SPB structure and organization. Self-associating coiled coils from Bbp1, Mps2, and Nbp1 were observed to form stable parallel homodimers in solution. Coiled-coil peptides from Bbp1 and Mps2 were also observed to hetero-associate. Experimental coiled-coil interaction data from this work and previous studies, as well as predicted and experimental structures for other SPB protein fragments and domains, were integrated to generate a model of the SPB structure.
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Affiliation(s)
- Nora Zizlsperger
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States
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Makio T, Nishikawa SI, Nakayama T, Nagai H, Endo T. Identification and characterization of a Jem1p ortholog ofCandida albicans: dissection of Jem1p functions in karyogamy and protein quality control inSaccharomyces cerevisiae. Genes Cells 2008; 13:1015-26. [DOI: 10.1111/j.1365-2443.2008.01223.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bornens M, Azimzadeh J. Origin and evolution of the centrosome. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 607:119-29. [PMID: 17977464 DOI: 10.1007/978-0-387-74021-8_10] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
In this brief account we specifically address the question of how the plasma membrane-associated basal body/axoneme of the unicellular ancestor of eukaryotes has evolved into the centrosome organelle through the several attempts to multicellularity. We propose that the connection between the flagellar apparatus and the nucleus has been a critical feature for leading to the centriole-based centrosome of metazoa, the Spindle Pole Body of fungi, or to the absence of any centrosome in seed plants. We further suggest that the evolution of this connection could be reflected in the evolution of the centrin proteins. We then review evidence showing that the evolution of the centrosome-based tubulin network has been correlated with the evolution of the cortical actin-based cleavage apparatus. Finally we argue that this coevolution had a major impact on the cell individuation process and on the evolution of multicellular organisms. We conclude that only the metazoan lineage evolved multicellularity without loosing the ancestral association of three basic cellular functions of the basal body/axoneme or the derived centrosome organelle, namely sensation, motion and division.
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Zhao Y, Feng J, Wang Z, Liang A, Yang B. Characterization of melittin binding to Euplotes octocarinatus centrin. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 70:884-887. [PMID: 18054274 DOI: 10.1016/j.saa.2007.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 10/03/2007] [Indexed: 05/25/2023]
Abstract
In the presence of 1.0mM Ca2+, the interaction between Euplotes octocarinatus centrin (EoCen) and melittin (ME) was studied by means of fluorescence spectra. In 0.1M N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid (Hepes) and 150mM NaCl at pH 7.4, fluorescence peak of ME was observed at about 353nm indicating that micro-environment of Tryptophan (Trp) residue in ME was hydrophilic. With the addition of 3.2x10(-4)M calcium saturated EoCen (holoEoCen), the peak of ME was blue-shifted to 339nm, which may be resulted from micro-environmental changes of the peptide. At the same time, fluorescence emission of ME was increased significantly suggesting that new complex of ME-holoEoCen was formed under the experimental conditions. Based on the fluorescence titration curves, the 1:1 stoichiometric ratio of holoEoCen to ME was confirmed. In addition, the conditional binding constant of holoEoCen with ME was calculated to be logKME-holoEoCen=6.59+/-0.14.
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Affiliation(s)
- Yaqin Zhao
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
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38
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Abstract
Rad23 is required for efficient protein degradation and performs an important role in nucleotide excision repair. Saccharomyces cerevisiae Rad23, and its human counterpart (hHR23), are present in a complex containing the DNA repair factor Rad4 (termed XPC, for xeroderma pigmentosum group C, in humans). XPC/hHR23 was also reported to bind centrin-2, a member of the superfamily of calcium-binding EF-hand proteins. We report here that yeast centrin, which is encoded by CDC31, is similarly present in a complex with Rad4/Rad23 (called NEF2). The interaction between Cdc31 and Rad23/Rad4 varied by growth phase and reflected oscillations in Cdc31 levels. Strikingly, a cdc31 mutant that formed a weaker interaction with Rad4 showed sensitivity to UV light. Based on the dual function of Rad23, in both DNA repair and protein degradation, we questioned if Cdc31 also participated in protein degradation. We report here that Cdc31 binds the proteasome and multiubiquitinated proteins through its carboxy-terminal EF-hand motifs. Moreover, cdc31 mutants were highly sensitive to drugs that cause protein damage, failed to efficiently degrade proteolytic substrates, and formed altered interactions with the proteasome. These findings reveal for the first time a new role for centrin/Cdc31 in protein degradation.
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Kleylein-Sohn J, Westendorf J, Le Clech M, Habedanck R, Stierhof YD, Nigg EA. Plk4-induced centriole biogenesis in human cells. Dev Cell 2007; 13:190-202. [PMID: 17681131 DOI: 10.1016/j.devcel.2007.07.002] [Citation(s) in RCA: 507] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 06/22/2007] [Accepted: 07/03/2007] [Indexed: 01/11/2023]
Abstract
We show that overexpression of Polo-like kinase 4 (Plk4) in human cells induces centrosome amplification through the simultaneous generation of multiple procentrioles adjoining each parental centriole. This provided an opportunity for dissecting centriole assembly and characterizing assembly intermediates. Critical components were identified and ordered into an assembly pathway through siRNA and localized through immunoelectron microscopy. Plk4, hSas-6, CPAP, Cep135, gamma-tubulin, and CP110 were required at different stages of procentriole formation and in association with different centriolar structures. Remarkably, hSas-6 associated only transiently with nascent procentrioles, whereas Cep135 and CPAP formed a core structure within the proximal lumen of both parental and nascent centrioles. Finally, CP110 was recruited early and then associated with the growing distal tips, indicating that centrioles elongate through insertion of alpha-/beta-tubulin underneath a CP110 cap. Collectively, these data afford a comprehensive view of the assembly pathway underlying centriole biogenesis in human cells.
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Affiliation(s)
- Julia Kleylein-Sohn
- Department of Cell Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
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Krebs J, Heizmann CW. Calcium-binding proteins and the EF-hand principle. CALCIUM - A MATTER OF LIFE OR DEATH 2007. [DOI: 10.1016/s0167-7306(06)41003-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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5 Studying Essential Genes: Generating and Using Promoter Fusions and Conditional Alleles. METHODS IN MICROBIOLOGY 2007. [DOI: 10.1016/s0580-9517(06)36005-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Giessl A, Trojan P, Rausch S, Pulvermüller A, Wolfrum U. Centrins, gatekeepers for the light-dependent translocation of transducin through the photoreceptor cell connecting cilium. Vision Res 2006; 46:4502-9. [PMID: 17027897 DOI: 10.1016/j.visres.2006.07.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 07/27/2006] [Accepted: 07/28/2006] [Indexed: 11/24/2022]
Abstract
Centrins are members of a highly conserved subgroup of the EF-hand superfamily of Ca(2+)-binding proteins commonly associated with centrosome-related structures. In the retina, centrins are also prominent components of the photoreceptor cell ciliary apparatus. Centrin isoforms are differentially localized at the basal body and in the lumen of the connecting cilium. All molecular exchanges between the inner and outer segments occur through this narrow connecting cilium. Ca(2+)-activated centrin isoforms bind to the visual heterotrimeric G-protein transducin via an interaction with the betagamma-subunit. Ca(2+)-dependent assemblies of centrin/G-protein complexes may regulate the transducin movement through the connecting cilium. Formation of this complex represents a novel mechanism in regulation of translocation of signaling proteins in sensory cells, as well as a potential link between molecular trafficking and signal transduction in general.
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Affiliation(s)
- Andreas Giessl
- Johannes Gutenberg-University, Institute of Zoology, Department of Cell and Matrix Biology, Mainz, Germany
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43
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Strawn LA, True HL. Deletion of RNQ1 gene reveals novel functional relationship between divergently transcribed Bik1p/CLIP-170 and Sfi1p in spindle pole body separation. Curr Genet 2006; 50:347-66. [PMID: 16972090 DOI: 10.1007/s00294-006-0098-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 08/17/2006] [Accepted: 08/19/2006] [Indexed: 02/03/2023]
Abstract
Spindle pole body (SPB; the microtubule organizing center in yeast) duplication is essential to form a bipolar spindle. The duplicated SPBs must then separate and migrate to opposite sides of the nucleus. We identified a novel functional relationship in SPB separation between the microtubule stabilizing protein Bik1p/CLIP-170 and the SPB half-bridge protein Sfi1p. A genetic interaction between BIK1 and SFI1 was discovered in a synthetic lethal screen using a strain deficient in the prion protein gene RNQ1. RNQ1 deletion reduced expression from the divergently transcribed BIK1, allowing us to identify genetic interactors with bik1. The sfi1-1 bik1 synthetic lethality was suppressed by over-expression of CIK1, KAR1, and PPH21. Genetic analysis indicated that the sfi1-1 bik1 synthetic lethality was unlikely related to the function of Bik1p in the dynein pathway or to defects in spindle position. Furthermore, a sfi1-1 Deltakip2 mutant was viable, suggesting that the Bik1p pool at the cytoplasmic microtubule plus-ends may not be required in sfi1-1. Microscopic examination indicated the sfi1-1 mutant was delayed in SPB duplication, SPB separation, or spindle elongation and the sfi-1 Deltabik1 double mutant arrested with duplicated but unseparated SPBs. These results suggest that Bik1p has a previously uncharacterized function in the separation of duplicated SPBs.
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Affiliation(s)
- Lisa A Strawn
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 S Euclid Ave, Campus Box 8228, St Louis, MO, 63110, USA.
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Jaspersen SL, Martin AE, Glazko G, Giddings TH, Morgan G, Mushegian A, Winey M. The Sad1-UNC-84 homology domain in Mps3 interacts with Mps2 to connect the spindle pole body with the nuclear envelope. ACTA ACUST UNITED AC 2006; 174:665-75. [PMID: 16923827 PMCID: PMC2064310 DOI: 10.1083/jcb.200601062] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The spindle pole body (SPB) is the sole site of microtubule nucleation in Saccharomyces cerevisiae; yet, details of its assembly are poorly understood. Integral membrane proteins including Mps2 anchor the soluble core SPB in the nuclear envelope. Adjacent to the core SPB is a membrane-associated SPB substructure known as the half-bridge, where SPB duplication and microtubule nucleation during G1 occurs. We found that the half-bridge component Mps3 is the budding yeast member of the SUN protein family (Sad1-UNC-84 homology) and provide evidence that it interacts with the Mps2 C terminus to tether the half-bridge to the core SPB. Mutants in the Mps3 SUN domain or Mps2 C terminus have SPB duplication and karyogamy defects that are consistent with the aberrant half-bridge structures we observe cytologically. The interaction between the Mps3 SUN domain and Mps2 C terminus is the first biochemical link known to connect the half-bridge with the core SPB. Association with Mps3 also defines a novel function for Mps2 during SPB duplication.
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Affiliation(s)
- Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
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Li S, Sandercock AM, Conduit P, Robinson CV, Williams RL, Kilmartin JV. Structural role of Sfi1p-centrin filaments in budding yeast spindle pole body duplication. ACTA ACUST UNITED AC 2006; 173:867-77. [PMID: 16785321 PMCID: PMC2063913 DOI: 10.1083/jcb.200603153] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Centrins are calmodulin-like proteins present in centrosomes and yeast spindle pole bodies (SPBs) and have essential functions in their duplication. The Saccharomyces cerevisiae centrin, Cdc31p, binds Sfi1p on multiple conserved repeats; both proteins localize to the SPB half-bridge, where the new SPB is assembled. The crystal structures of Sfi1p–centrin complexes containing several repeats show Sfi1p as an α helix with centrins wrapped around each repeat and similar centrin–centrin contacts between each repeat. Electron microscopy (EM) shadowing of an Sfi1p–centrin complex with 15 Sfi1 repeats and 15 centrins bound showed filaments 60 nm long, compatible with all the Sfi1 repeats as a continuous α helix. Immuno-EM localization of the Sfi1p N and C termini showed Sfi1p–centrin filaments spanning the length of the half-bridge with the Sfi1p N terminus at the SPB. This suggests a model for SPB duplication where the half-bridge doubles in length by association of the Sfi1p C termini, thereby providing a new Sfi1p N terminus to initiate SPB assembly.
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Affiliation(s)
- Sam Li
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, England, UK
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Meyn SM, Seda C, Campbell M, Weiss KL, Hu H, Pastrana-Rios B, Chazin WJ. The biochemical effect of Ser167 phosphorylation on Chlamydomonas reinhardtii centrin. Biochem Biophys Res Commun 2006; 342:342-8. [PMID: 16480960 DOI: 10.1016/j.bbrc.2006.01.155] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 01/29/2006] [Indexed: 11/19/2022]
Abstract
Centrin is an EF-hand calcium-binding protein found in microtubule organizing centers of organisms ranging from algae and yeast to man. Phosphorylation in the centrin C-terminal domain occurs in mitosis and is associated with alterations in contractile fibers. To obtain insight into the structural basis for the functional effect of phosphorylation, Chlamydomonas reinhardtii centrin C-terminal domain phosphorylated at Ser167 (pCRC-C) has been produced and characterized. The structure of pCRC-C was compared to the unmodified protein by NMR spectroscopy. The effect of phosphorylation on target binding was examined for the complex of pCRC-C and a 19 residue centrin-binding fragment of Kar1. Remarkably, the efficient and selective phosphorylation by PKA was suppressed in the complex. Moreover, comparisons of NMR chemical shift differences induced by phosphorylation reveal a greater effect from phosphorylation in the context of the Kar1 complex than for the free protein. These results directly demonstrate that phosphorylation modulates the structure and biochemical activities of centrin.
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Affiliation(s)
- Susan M Meyn
- Department of Biochemistry, Center for Structural Biology, 5140 BIOSCI/MRBIII, Vanderbilt University, Nashville, TN 37232-8725, USA
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Sheehan JH, Bunick CG, Hu H, Fagan PA, Meyn SM, Chazin WJ. Structure of the N-terminal Calcium Sensor Domain of Centrin Reveals the Biochemical Basis for Domain-specific Function. J Biol Chem 2006; 281:2876-81. [PMID: 16317001 DOI: 10.1074/jbc.m509886200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Centrin is an essential component of microtubule-organizing centers in organisms ranging from algae and yeast to humans. It is an EF-hand calcium-binding protein with homology to calmodulin but distinct calcium binding properties. In a previously proposed model, the C-terminal domain of centrin serves as a constitutive anchor to target proteins, and the N-terminal domain serves as the sensor of calcium signals. The three-dimensional structure of the N-terminal domain of Chlamydomonas rheinhardtii centrin has been determined in the presence of calcium by solution NMR spectroscopy. The domain is found to occupy an open conformation typical of EF-hand calcium sensors. Comparison of the N- and C-terminal domains of centrin reveals a structural and biochemical basis for the domain specificity of interactions with its cellular targets and the distinct nature of centrin relative to other EF-hand proteins. An NMR titration of the centrin N-terminal domain with a fragment of the known centrin target Sfi1 reveals binding of the peptide to a discrete site on the protein, which supports the proposal that the N-terminal domain serves as a calcium sensor in centrin.
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Affiliation(s)
- Jonathan H Sheehan
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232-8725, USA
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Geimer S, Melkonian M. Centrin scaffold in Chlamydomonas reinhardtii revealed by immunoelectron microscopy. EUKARYOTIC CELL 2005; 4:1253-63. [PMID: 16002651 PMCID: PMC1168961 DOI: 10.1128/ec.4.7.1253-1263.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the flagellate green alga Chlamydomonas reinhardtii the Ca(2+)-binding EF-hand protein centrin is encoded by a single-copy gene. Previous studies have localized the protein to four distinct structures in the flagellar apparatus: the nucleus-basal body connector, the distal connecting fiber, the flagellar transitional region, and the axoneme. To explain the disjunctive distribution of centrin, the interaction of centrin with as yet unknown specific centrin-binding proteins has been implied. Here, we demonstrate using serial section postembedding immunoelectron microscopy of isolated cytoskeletons that centrin is located in additional structures (transitional fibers and basal body lumen) and that the centrin-containing structures of the basal apparatus are likely part of a continuous filamentous scaffold that extends from the nucleus to the flagellar bases. In addition, we show that centrin is located in the distal lumen of the basal body in a rotationally asymmetric structure, the V-shaped filament system. This novel centrin-containing structure has also been detected near the distal end of the probasal bodies. Taken together, these results suggest a role for a rotationally asymmetric centrin "seed" in the growth and development of the centrin scaffold following replication of the basal apparatus.
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Affiliation(s)
- Stefan Geimer
- Universität Bayreuth, Biologie/Elektronenmikroskopie NW I / B 1, Universitätsstr. 30, D-95447 Bayreuth, Germany.
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Abstract
Nucleation of microtubules by eukaryotic microtubule organizing centers (MTOCs) is required for a variety of functions, including chromosome segregation during mitosis and meiosis, cytokinesis, fertilization, cellular morphogenesis, cell motility, and intracellular trafficking. Analysis of MTOCs from different organisms shows that the structure of these organelles is widely varied even though they all share the function of microtubule nucleation. Despite their morphological diversity, many components and regulators of MTOCs, as well as principles in their assembly, seem to be conserved. This review focuses on one of the best-characterized MTOCs, the budding yeast spindle pole body (SPB). We review what is known about its structure, protein composition, duplication, regulation, and functions. In addition, we discuss how studies of the yeast SPB have aided investigation of other MTOCs, most notably the centrosome of animal cells.
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Affiliation(s)
- Sue L Jaspersen
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA.
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Cox JA, Tirone F, Durussel I, Firanescu C, Blouquit Y, Duchambon P, Craescu CT. Calcium and Magnesium Binding to Human Centrin 3 and Interaction with Target Peptides. Biochemistry 2004; 44:840-50. [PMID: 15654740 DOI: 10.1021/bi048294e] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There are four isoforms of centrin in mammals, with variable sequence, tissue expression, and functional properties. We have recently characterized a number of structural, ion, and target binding properties of human centrin isoform HsCen2. This paper reports a similar characterization of HsCen3, overexpressed in Escherichia coli and purified by phase-reversed chromatography. Equilibrium and dynamic binding studies revealed that HsCen3 has one mixed Ca(2+)/Mg(2+) binding site of high affinity (K(d) = 3 and 10 microM for Ca(2+) and Mg(2+), respectively) and two Ca(2+)-specific sites of low affinity (K(d) = 140 microM). The metal-free protein is fragmented by an unidentified protease into a polypeptide segment of 11 kDa, which was purified by HPLC, and identified by mass spectrometry as the segment of residues 21-112. Similarly, controlled trypsinolysis on Ca(2+)-bound HsCen3 yielded a mixture of segments of residues 1-124 and 1-125. The Ca(2+)/Mg(2+) site could be assigned to this segment and thus resides in the N-terminal half of HsCen3. Temperature denaturation experiments, circular dichroism, and utilization of fluorescence hydrophobic probes allowed us to propose that the metal-free protein has molten globule characteristics and that the dication-bound forms are compact with a polar surface for the Mg(2+) form and a hydrophobic exposed surface for the Ca(2+) form. Thus, HsCen3 could be classified as a Ca(2+) sensor protein. In addition, it is able to bind strongly to a model target peptide (melittin), as well as to peptides derived from the protein XPC and Kar1p, with a moderate Ca(2+) dependence.
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Affiliation(s)
- Jos A Cox
- Department of Biochemistry, University of Geneva, Geneva 4, Switzerland
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