1
|
Mii Y. Understanding and manipulating extracellular behaviors of Wnt ligands. In Vitro Cell Dev Biol Anim 2024; 60:441-448. [PMID: 38379096 DOI: 10.1007/s11626-024-00856-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/17/2024] [Indexed: 02/22/2024]
Abstract
Wnt, a family of secreted signaling proteins, serves diverse functions in embryogenesis, organogenesis, cancer, and stem cell functions. In the context of development, Wnt has been considered a representative morphogen, forming concentration gradients to give positional information to cells or tissues. However, although gradients are often illustrated in schemata, the reality of concentration gradients, or in other words, actual spatial distribution of Wnt ligands, and their behaviors in the extracellular space still remain poorly known. To understand extracellular behavior of Wnt ligands, quantitative analyses such as fluorescence correlation spectroscopy (FCS) and fluorescence recovery after photobleaching (FRAP) are highly informative because Wnt dispersal involves physical and biochemical processes, such as diffusion and binding to or dissociation from cell surface molecules, including heparan sulfate proteoglycans (HSPGs). Here, I briefly discuss representative methods to quantify morphogen dynamics. In addition, I discuss molecular manipulations of morphogens, mainly focusing on use of protein binders, and synthetic biology of morphogens as indicators of current and future directions in this field.
Collapse
Affiliation(s)
- Yusuke Mii
- National Institute for Basic Biology (NIBB) and Exploratory Research Center On Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, 444-8787, Japan.
| |
Collapse
|
2
|
Barbiero M, Cirillo L, Veerapathiran S, Coates C, Ruffilli C, Pines J. Cell cycle-dependent binding between Cyclin B1 and Cdk1 revealed by time-resolved fluorescence correlation spectroscopy. Open Biol 2022; 12:220057. [PMID: 35765818 PMCID: PMC9240681 DOI: 10.1098/rsob.220057] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/07/2022] [Indexed: 01/04/2023] Open
Abstract
Measuring the dynamics with which the regulatory complexes assemble and disassemble is a crucial barrier to our understanding of how the cell cycle is controlled that until now has been difficult to address. This considerable gap in our understanding is due to the difficulty of reconciling biochemical assays with single cell-based techniques, but recent advances in microscopy and gene editing techniques now enable the measurement of the kinetics of protein-protein interaction in living cells. Here, we apply fluorescence correlation spectroscopy and fluorescence cross-correlation spectroscopy to study the dynamics of the cell cycle machinery, beginning with Cyclin B1 and its binding to its partner kinase Cdk1 that together form the major mitotic kinase. Although Cyclin B1 and Cdk1 are known to bind with high affinity, our results reveal that in living cells there is a pool of Cyclin B1 that is not bound to Cdk1. Furthermore, we provide evidence that the affinity of Cyclin B1 for Cdk1 increases during the cell cycle, indicating that the assembly of the complex is a regulated step. Our work lays the groundwork for studying the kinetics of protein complex assembly and disassembly during the cell cycle in living cells.
Collapse
Affiliation(s)
- Martina Barbiero
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Luca Cirillo
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Sapthaswaran Veerapathiran
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Catherine Coates
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Camilla Ruffilli
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| | - Jonathon Pines
- Cancer Biology, The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, London SW3 6JB, UK
| |
Collapse
|
3
|
New insights into the proteins interacting with the promoters of silkworm fibroin genes. Sci Rep 2021; 11:15880. [PMID: 34354143 PMCID: PMC8342599 DOI: 10.1038/s41598-021-95400-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/26/2021] [Indexed: 12/02/2022] Open
Abstract
The silkworm, Bombyx mori, is a silk-producing insect that has contributed greatly to human society. The silk gland of B. mori is a specialized organ responsible for synthesizing silk fibroin and sericin proteins under control of numerous factors. However, which factors are involved in direct silk protein synthesis regulation remains largely unknown. We report the identification of promoter-interacting proteins (PIPs) necessary for the regulation of genes encoding fibroin proteins, including the fibroin heavy chain (fibH), fibroin light chain (fibL), and a 25-kD polypeptide protein (P25). In the fourth larval molting stage (M4) or day 5 fifth-instar larvae (L5D5), a total of 198, 292, and 247 or 330, 305, and 460 proteins interacting with the promoter region of fibH, fibL and P25, respectively, were identified from the posterior silk gland by DNA pull-down combined with mass spectrometry. Many PIPs were particularly involved in ribosome- and metabolism-related pathways. Additionally, 135 and 212 proteins were identified as common PIPs of fibH, fibL and P25 in M4 and L5D5, respectively. Among all PIPs, we identified 31 potential transcription factors, such as Y-box and poly A-binding proteins, which play roles in nucleotide binding, ATP binding, or protein folding. This study provides the first in-depth profile of proteins interacting with fibroin gene promoters and contributes to a better understanding of silk protein synthesis regulation.
Collapse
|
4
|
Mii Y, Nakazato K, Pack CG, Ikeda T, Sako Y, Mochizuki A, Taira M, Takada S. Quantitative analyses reveal extracellular dynamics of Wnt ligands in Xenopus embryos. eLife 2021; 10:55108. [PMID: 33904408 PMCID: PMC8139832 DOI: 10.7554/elife.55108] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/23/2021] [Indexed: 12/11/2022] Open
Abstract
The mechanism of intercellular transport of Wnt ligands is still a matter of debate. To better understand this issue, we examined the distribution and dynamics of Wnt8 in Xenopus embryos. While Venus-tagged Wnt8 was found on the surfaces of cells close to Wnt-producing cells, we also detected its dispersal over distances of 15 cell diameters. A combination of fluorescence correlation spectroscopy and quantitative imaging suggested that only a small proportion of Wnt8 ligands diffuses freely, whereas most Wnt8 molecules are bound to cell surfaces. Fluorescence decay after photoconversion showed that Wnt8 ligands bound on cell surfaces decrease exponentially, suggesting a dynamic exchange of bound forms of Wnt ligands. Mathematical modeling based on this exchange recapitulates a graded distribution of bound, but not free, Wnt ligands. Based on these results, we propose that Wnt distribution in tissues is controlled by a dynamic exchange of its abundant bound and rare free populations.
Collapse
Affiliation(s)
- Yusuke Mii
- National Institute for Basic Biology and Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Japan.,The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan.,Japan Science and Technology Agency (JST), PRESTO, Kawaguchi, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | | | - Chan-Gi Pack
- Cellular Informatics Laboratory, RIKEN, Wako, Japan.,ASAN Institute for Life Sciences, ASAN Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Takafumi Ikeda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, Wako, Japan
| | - Atsushi Mochizuki
- Theoretical Biology Laboratory, RIKEN, Wako, Japan.,Laboratory of Mathematical Biology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Masanori Taira
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.,Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Tokyo, Japan
| | - Shinji Takada
- National Institute for Basic Biology and Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Japan.,The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Japan
| |
Collapse
|
5
|
Takei N, Takada Y, Kawamura S, Sato K, Saitoh A, Bormann J, Yuen WS, Carroll J, Kotani T. Changes in subcellular structures and states of pumilio 1 regulate the translation of target Mad2 and cyclin B1 mRNAs. J Cell Sci 2020; 133:jcs249128. [PMID: 33148609 DOI: 10.1242/jcs.249128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/22/2020] [Indexed: 12/12/2022] Open
Abstract
Temporal and spatial control of mRNA translation has emerged as a major mechanism for promoting diverse biological processes. However, the molecular nature of temporal and spatial control of translation remains unclear. In oocytes, many mRNAs are deposited as a translationally repressed form and are translated at appropriate times to promote the progression of meiosis and development. Here, we show that changes in subcellular structures and states of the RNA-binding protein pumilio 1 (Pum1) regulate the translation of target mRNAs and progression of oocyte maturation. Pum1 was shown to bind to Mad2 (also known as Mad2l1) and cyclin B1 mRNAs, assemble highly clustered aggregates, and surround Mad2 and cyclin B1 RNA granules in mouse oocytes. These Pum1 aggregates were dissolved prior to the translational activation of target mRNAs, possibly through phosphorylation. Stabilization of Pum1 aggregates prevented the translational activation of target mRNAs and progression of oocyte maturation. Together, our results provide an aggregation-dissolution model for the temporal and spatial control of translation.
Collapse
Affiliation(s)
- Natsumi Takei
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Takada
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Shohei Kawamura
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Keisuke Sato
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Atsushi Saitoh
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Jenny Bormann
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Wai Shan Yuen
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - John Carroll
- Development and Stem Cells Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Tomoya Kotani
- Biosystems Science Course, Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| |
Collapse
|
6
|
Price RM, Budzyński MA, Kundra S, Teves SS. Advances in visualizing transcription factor - DNA interactions. Genome 2020; 64:449-466. [PMID: 33113335 DOI: 10.1139/gen-2020-0086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
At the heart of the transcription process is the specific interaction between transcription factors (TFs) and their target DNA sequences. Decades of molecular biology research have led to unprecedented insights into how TFs access the genome to regulate transcription. In the last 20 years, advances in microscopy have enabled scientists to add imaging as a powerful tool in probing two specific aspects of TF-DNA interactions: structure and dynamics. In this review, we examine how applications of diverse imaging technologies can provide structural and dynamic information that complements insights gained from molecular biology assays. As a case study, we discuss how applications of advanced imaging techniques have reshaped our understanding of TF behavior across the cell cycle, leading to a rethinking in the field of mitotic bookmarking.
Collapse
Affiliation(s)
- Rachel M Price
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Marek A Budzyński
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Shivani Kundra
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Sheila S Teves
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.,Department of Biochemistry and Molecular Biology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| |
Collapse
|
7
|
Jin X, Hapsari ND, Lee S, Jo K. DNA binding fluorescent proteins as single-molecule probes. Analyst 2020; 145:4079-4095. [DOI: 10.1039/d0an00218f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
DNA binding fluorescent proteins are useful probes for a broad range of biological applications.
Collapse
Affiliation(s)
- Xuelin Jin
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
| | - Natalia Diyah Hapsari
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
- Chemistry Education Program
| | - Seonghyun Lee
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
| | - Kyubong Jo
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
| |
Collapse
|
8
|
Sato Y, Kamijo K, Tsutsumi M, Murakami Y, Takahashi M. Nonmuscle myosin IIA and IIB differently suppress microtubule growth to stabilize cell morphology. J Biochem 2019; 167:25-39. [DOI: 10.1093/jb/mvz082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/22/2019] [Indexed: 12/21/2022] Open
Abstract
Abstract
Precise regulation of cytoskeletal dynamics is important in many fundamental cellular processes such as cell shape determination. Actin and microtubule (MT) cytoskeletons mutually regulate their stability and dynamics. Nonmuscle myosin II (NMII) is a candidate protein that mediates the actin–MT crosstalk. NMII regulates the stability and dynamics of actin filaments to control cell morphology. Additionally, previous reports suggest that NMII-dependent cellular contractility regulates MT dynamics, and MTs also control cell morphology; however, the detailed mechanism whereby NMII regulates MT dynamics and the relationship among actin dynamics, MT dynamics and cell morphology remain unclear. The present study explores the roles of two well-characterized NMII isoforms, NMIIA and NMIIB, on the regulation of MT growth dynamics and cell morphology. We performed RNAi and drug experiments and demonstrated the NMII isoform-specific mechanisms—NMIIA-dependent cellular contractility upregulates the expression of some mammalian diaphanous-related formin (mDia) proteins that suppress MT dynamics; NMIIB-dependent inhibition of actin depolymerization suppresses MT growth independently of cellular contractility. The depletion of either NMIIA or NMIIB resulted in the increase in cellular morphological dynamicity, which was alleviated by the perturbation of MT dynamics. Thus, the NMII-dependent control of cell morphology significantly relies on MT dynamics.
Collapse
Affiliation(s)
- Yuta Sato
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
| | - Keiju Kamijo
- Division of Anatomy and Cell Biology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai Miyagi, Japan
| | - Motosuke Tsutsumi
- Research Institute for Electronic Science, Hokkaido University, Kita 20, Nishi 10, Kita-ku, Sapporo Hokkaido, Japan
| | - Yota Murakami
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
| | - Masayuki Takahashi
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
- Department of Chemistry, Faculty of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo Hokkaido, Japan
| |
Collapse
|
9
|
Insights into the regulatory characteristics of silkworm fibroin gene promoters using a modified Gal4/UAS system. Transgenic Res 2019; 28:627-636. [DOI: 10.1007/s11248-019-00175-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 09/25/2019] [Indexed: 10/25/2022]
|
10
|
Di Bona M, Mancini MA, Mazza D, Vicidomini G, Diaspro A, Lanzanò L. Measuring Mobility in Chromatin by Intensity-Sorted FCS. Biophys J 2019; 116:987-999. [PMID: 30819566 PMCID: PMC6428914 DOI: 10.1016/j.bpj.2019.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/14/2019] [Accepted: 02/08/2019] [Indexed: 12/12/2022] Open
Abstract
The architectural organization of chromatin can play an important role in genome regulation by affecting the mobility of molecules within its surroundings via binding interactions and molecular crowding. The diffusion of molecules at specific locations in the nucleus can be studied by fluorescence correlation spectroscopy (FCS), a well-established technique based on the analysis of fluorescence intensity fluctuations detected in a confocal observation volume. However, detecting subtle variations of mobility between different chromatin regions remains challenging with currently available FCS methods. Here, we introduce a method that samples multiple positions by slowly scanning the FCS observation volume across the nucleus. Analyzing the data in short time segments, we preserve the high temporal resolution of single-point FCS while probing different nuclear regions in the same cell. Using the intensity level of the probe (or a DNA marker) as a reference, we efficiently sort the FCS segments into different populations and obtain average correlation functions that are associated to different chromatin regions. This sorting and averaging strategy renders the method statistically robust while preserving the observation of intranuclear variations of mobility. Using this approach, we quantified diffusion of monomeric GFP in high versus low chromatin density regions. We found that GFP mobility was reduced in heterochromatin, especially within perinucleolar heterochromatin. Moreover, we found that modulation of chromatin compaction by ATP depletion, or treatment with solutions of different osmolarity, differentially affected the ratio of diffusion in both regions. Then, we used the approach to probe the mobility of estrogen receptor-α in the vicinity of an integrated multicopy prolactin gene array. Finally, we discussed the coupling of this method with stimulated emission depletion FCS for performing FCS at subdiffraction spatial scales.
Collapse
Affiliation(s)
- Melody Di Bona
- Nanoscopy and Nikon Imaging Center, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics, University of Genoa, Genoa, Italy
| | - Michael A Mancini
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
| | - Davide Mazza
- Experimental Imaging Center Ospedale San Raffaele, Milano, Italy; The European Center for Nanomedicine, Milano, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Alberto Diaspro
- Nanoscopy and Nikon Imaging Center, Istituto Italiano di Tecnologia, Genoa, Italy; Department of Physics, University of Genoa, Genoa, Italy.
| | - Luca Lanzanò
- Nanoscopy and Nikon Imaging Center, Istituto Italiano di Tecnologia, Genoa, Italy.
| |
Collapse
|
11
|
Papadopoulos DK, Skouloudaki K, Engström Y, Terenius L, Rigler R, Zechner C, Vukojević V, Tomancak P. Control of Hox transcription factor concentration and cell-to-cell variability by an auto-regulatory switch. Development 2019; 146:dev.168179. [PMID: 30642837 PMCID: PMC6602345 DOI: 10.1242/dev.168179] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/20/2018] [Indexed: 01/13/2023]
Abstract
The variability in transcription factor concentration among cells is an important developmental determinant, yet how variability is controlled remains poorly understood. Studies of variability have focused predominantly on monitoring mRNA production noise. Little information exists about transcription factor protein variability, as this requires the use of quantitative methods with single-molecule sensitivity. Using Fluorescence Correlation Spectroscopy (FCS), we have characterized the concentration and variability of 14 endogenously tagged TFs in live Drosophila imaginal discs. For the Hox TF Antennapedia, we investigated whether protein variability results from random stochastic events or is developmentally regulated. We found that Antennapedia transitioned from low concentration/high variability early, to high concentration/low variability later, in development. FCS and temporally resolved genetic studies uncovered that Antennapedia itself is necessary and sufficient to drive a developmental regulatory switch from auto-activation to auto-repression, thereby reducing variability. This switch is controlled by progressive changes in relative concentrations of preferentially activating and repressing Antennapedia isoforms, which bind chromatin with different affinities. Mathematical modeling demonstrated that the experimentally supported auto-regulatory circuit can explain the increase of Antennapedia concentration and suppression of variability over time. Summary: Preferentially repressing and activating isoforms of the Hox transcription factor Antennapedia elicit a developmental regulatory switch from auto-activation to auto-repression that increases concentration and suppresses cell-to-cell variability over time.
Collapse
Affiliation(s)
| | - Kassiani Skouloudaki
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Ylva Engström
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Lars Terenius
- Center for Molecular Medicine (CMM), Department of Clinical Neuroscience, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Rudolf Rigler
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden.,Laboratory of Biomedical Optics, Swiss Federal Institute of Technology, 1015 Lausanne, Switzerland
| | - Christoph Zechner
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.,Center for Systems Biology Dresden, 01307 Dresden, Germany
| | - Vladana Vukojević
- Center for Molecular Medicine (CMM), Department of Clinical Neuroscience, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Pavel Tomancak
- Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| |
Collapse
|
12
|
Mapping the Dynamics of the Glucocorticoid Receptor within the Nuclear Landscape. Sci Rep 2017; 7:6219. [PMID: 28740156 PMCID: PMC5524710 DOI: 10.1038/s41598-017-06676-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/15/2017] [Indexed: 12/28/2022] Open
Abstract
The distribution of the transcription machinery among different sub-nuclear domains raises the question on how the architecture of the nucleus modulates the transcriptional response. Here, we used fluorescence fluctuation analyses to quantitatively explore the organization of the glucocorticoid receptor (GR) in the interphase nucleus of living cells. We found that this ligand-activated transcription factor diffuses within the nucleus and dynamically interacts with bodies enriched in the coregulator NCoA-2, DNA-dependent foci and chromatin targets. The distribution of the receptor among the nuclear compartments depends on NCoA-2 and the conformation of the receptor as assessed with synthetic ligands and GR mutants with impaired transcriptional abilities. Our results suggest that the partition of the receptor in different nuclear reservoirs ultimately regulates the concentration of receptor available for the interaction with specific targets, and thus has an impact on transcription regulation.
Collapse
|