1
|
Loyer N, Hogg EKJ, Shaw HG, Pasztor A, Murray DH, Findlay GM, Januschke J. A CDK1 phosphorylation site on Drosophila PAR-3 regulates neuroblast polarisation and sensory organ formation. eLife 2024; 13:e97902. [PMID: 38869055 PMCID: PMC11216751 DOI: 10.7554/elife.97902] [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: 03/27/2024] [Accepted: 05/08/2024] [Indexed: 06/14/2024] Open
Abstract
The generation of distinct cell fates during development depends on asymmetric cell division of progenitor cells. In the central and peripheral nervous system of Drosophila, progenitor cells respectively called neuroblasts or sensory organ precursors use PAR polarity during mitosis to control cell fate determination in their daughter cells. How polarity and the cell cycle are coupled, and how the cell cycle machinery regulates PAR protein function and cell fate determination is poorly understood. Here, we generate an analog sensitive allele of CDK1 and reveal that its partial inhibition weakens but does not abolish apical polarity in embryonic and larval neuroblasts and leads to defects in polarisation of fate determinants. We describe a novel in vivo phosphorylation of Bazooka, the Drosophila homolog of PAR-3, on Serine180, a consensus CDK phosphorylation site. In some tissular contexts, phosphorylation of Serine180 occurs in asymmetrically dividing cells but not in their symmetrically dividing neighbours. In neuroblasts, Serine180 phosphomutants disrupt the timing of basal polarisation. Serine180 phosphomutants also affect the specification and binary cell fate determination of sensory organ precursors as well as Baz localisation during their asymmetric cell divisions. Finally, we show that CDK1 phosphorylates Serine-S180 and an equivalent Serine on human PAR-3 in vitro.
Collapse
Affiliation(s)
- Nicolas Loyer
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
| | - Elizabeth KJ Hogg
- MRC PPU, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Hayley G Shaw
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
| | - Anna Pasztor
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
- MRC PPU, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - David H Murray
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
| | - Greg M Findlay
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
- MRC PPU, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Jens Januschke
- Molecular, Cell and Developmental Biology, University of DundeeDundeeUnited Kingdom
| |
Collapse
|
2
|
Fishburn AT, Florio CJ, Lopez NJ, Link NL, Shah PS. Molecular functions of ANKLE2 and its implications in human disease. Dis Model Mech 2024; 17:dmm050554. [PMID: 38691001 PMCID: PMC11103583 DOI: 10.1242/dmm.050554] [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] [Indexed: 05/03/2024] Open
Abstract
Ankyrin repeat and LEM domain-containing 2 (ANKLE2) is a scaffolding protein with established roles in cell division and development, the dysfunction of which is increasingly implicated in human disease. ANKLE2 regulates nuclear envelope disassembly at the onset of mitosis and its reassembly after chromosome segregation. ANKLE2 dysfunction is associated with abnormal nuclear morphology and cell division. It regulates the nuclear envelope by mediating protein-protein interactions with barrier to autointegration factor (BANF1; also known as BAF) and with the kinase and phosphatase that modulate the phosphorylation state of BAF. In brain development, ANKLE2 is crucial for proper asymmetric division of neural progenitor cells. In humans, pathogenic loss-of-function mutations in ANKLE2 are associated with primary congenital microcephaly, a condition in which the brain is not properly developed at birth. ANKLE2 is also linked to other disease pathologies, including congenital Zika syndrome, cancer and tauopathy. Here, we review the molecular roles of ANKLE2 and the recent literature on human diseases caused by its dysfunction.
Collapse
Affiliation(s)
- Adam T. Fishburn
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Cole J. Florio
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Nick J. Lopez
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Nichole L. Link
- Department of Neurobiology, University of Utah, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Priya S. Shah
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
- Department of Chemical Engineering, University of California, One Shields Avenue, Davis, CA 95616, USA
| |
Collapse
|
3
|
Penkert RR, LaFoya B, Moholt-Siebert L, Vargas E, Welch SE, Prehoda KE. The Drosophila neuroblast polarity cycle at a glance. J Cell Sci 2024; 137:jcs261789. [PMID: 38465513 PMCID: PMC10984279 DOI: 10.1242/jcs.261789] [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] [Indexed: 03/12/2024] Open
Abstract
Drosophila neural stem cells, or neuroblasts, rapidly proliferate during embryonic and larval development to populate the central nervous system. Neuroblasts divide asymmetrically to create cellular diversity, with each division producing one sibling cell that retains the neuroblast fate and another that differentiates into glia or neurons. This asymmetric outcome is mediated by the transient polarization of numerous factors to the cell cortex during mitosis. The powerful genetics and outstanding imaging tractability of the neuroblast make it an excellent model system for studying the mechanisms of cell polarity. This Cell Science at a Glance article and the accompanying poster explore the phases of the neuroblast polarity cycle and the regulatory circuits that control them. We discuss the key features of the cycle - the targeted recruitment of proteins to specific regions of the plasma membrane and multiple phases of highly dynamic actomyosin-dependent cortical flows that pattern both protein distribution and membrane structure.
Collapse
|
4
|
Ko BS, Han MH, Kwon MJ, Cha DG, Ji Y, Park ES, Jeon MJ, Kim S, Lee K, Choi YH, Lee J, Torras-Llort M, Yoon KJ, Lee H, Kim JK, Lee SB. Baf-mediated transcriptional regulation of teashirt is essential for the development of neural progenitor cell lineages. Exp Mol Med 2024; 56:422-440. [PMID: 38374207 PMCID: PMC10907700 DOI: 10.1038/s12276-024-01169-3] [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: 03/10/2023] [Revised: 09/20/2023] [Accepted: 12/10/2023] [Indexed: 02/21/2024] Open
Abstract
Accumulating evidence hints heterochromatin anchoring to the inner nuclear membrane as an upstream regulatory process of gene expression. Given that the formation of neural progenitor cell lineages and the subsequent maintenance of postmitotic neuronal cell identity critically rely on transcriptional regulation, it seems possible that the development of neuronal cells is influenced by cell type-specific and/or context-dependent programmed regulation of heterochromatin anchoring. Here, we explored this possibility by genetically disrupting the evolutionarily conserved barrier-to-autointegration factor (Baf) in the Drosophila nervous system. Through single-cell RNA sequencing, we demonstrated that Baf knockdown induces prominent transcriptomic changes, particularly in type I neuroblasts. Among the differentially expressed genes, our genetic analyses identified teashirt (tsh), a transcription factor that interacts with beta-catenin, to be closely associated with Baf knockdown-induced phenotypes that were suppressed by the overexpression of tsh or beta-catenin. We also found that Baf and tsh colocalized in a region adjacent to heterochromatin in type I NBs. Notably, the subnuclear localization pattern remained unchanged when one of these two proteins was knocked down, indicating that both proteins contribute to the anchoring of heterochromatin to the inner nuclear membrane. Overall, this study reveals that the Baf-mediated transcriptional regulation of teashirt is a novel molecular mechanism that regulates the development of neural progenitor cell lineages.
Collapse
Affiliation(s)
- Byung Su Ko
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Myeong Hoon Han
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Min Jee Kwon
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Dong Gon Cha
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Yuri Ji
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Eun Seo Park
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | - Min Jae Jeon
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
| | - Somi Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kyeongho Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu, 42988, Republic of Korea
| | - Yoon Ha Choi
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jusung Lee
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea
| | | | - Ki-Jun Yoon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hyosang Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, DGIST, Daegu, 42988, Republic of Korea
| | - Jong Kyoung Kim
- Department of New Biology, DGIST, Daegu, 42988, Republic of Korea.
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
| | - Sung Bae Lee
- Department of Brain Sciences, DGIST, Daegu, 42988, Republic of Korea.
| |
Collapse
|
5
|
Jones KA, Drummond ML, Penkert RR, Prehoda KE. Cooperative regulation of C1-domain membrane recruitment polarizes atypical protein kinase C. J Cell Biol 2023; 222:e202112143. [PMID: 37589718 PMCID: PMC10435729 DOI: 10.1083/jcb.202112143] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/15/2023] [Accepted: 08/01/2023] [Indexed: 08/18/2023] Open
Abstract
Recruitment of the Par complex protein atypical protein kinase C (aPKC) to a specific membrane domain is a key step in the polarization of animal cells. While numerous proteins and phospholipids interact with aPKC, how these interactions cooperate to control its membrane recruitment has been unknown. Here, we identify aPKC's C1 domain as a phospholipid interaction module that targets aPKC to the membrane of Drosophila neural stem cells (NSCs). The isolated C1 binds the NSC membrane in an unpolarized manner during interphase and mitosis and is uniquely sufficient among aPKC domains for targeting. Other domains, including the catalytic module and those that bind the upstream regulators Par-6 and Bazooka, restrict C1's membrane targeting activity-spatially and temporally-to the apical NSC membrane during mitosis. Our results suggest that aPKC polarity results from cooperative activation of autoinhibited C1-mediated membrane binding activity.
Collapse
Affiliation(s)
- Kimberly A. Jones
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Michael L. Drummond
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Rhiannon R. Penkert
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Kenneth E. Prehoda
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| |
Collapse
|
6
|
Samanta P, Bhowmik A, Biswas S, Sarkar R, Ghosh R, Pakhira S, Mondal M, Sen S, Saha P, Hajra S. Therapeutic Effectiveness of Anticancer Agents Targeting Different Signaling Molecules Involved in Asymmetric Division of Cancer Stem Cell. Stem Cell Rev Rep 2023:10.1007/s12015-023-10523-3. [PMID: 36952080 DOI: 10.1007/s12015-023-10523-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2023] [Indexed: 03/24/2023]
Abstract
Intra-tumoral heterogeneity is maintained by cancer stem cells (CSCs) with dysregulated self-renewal and asymmetric cell division (ACD). According to the cancer stem cell theory, by ACD a CSC can generate two daughter progenies with different fates such as one cancer stem cell and one differentiated cell. Therefore, this type of mitotic division supports vital process of the maintenance of CSC population. But this CSC pool reservation by ACD complicates the treatment of cancer patients, as CSCs give rise to aggressive clones which are prone to metastasis and drug-insensitivity. Hence, identification of therapeutic modalities which can target ACD of cancer stem cell is an intriguing part of cancer research. In this review, other than the discussion about the extrinsic inducers of ACD role of different proteins, miRNAs and lncRNAs in this type of cell division is also mentioned. Other than these, mode of action of the proven and potential drugs targeting ACD of CSC is also discussed here.
Collapse
Affiliation(s)
- Priya Samanta
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Arijit Bhowmik
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India.
| | - Souradeep Biswas
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Rupali Sarkar
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Rituparna Ghosh
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Shampa Pakhira
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Mrinmoyee Mondal
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Soummadeep Sen
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Prosenjit Saha
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India
| | - Subhadip Hajra
- Department of Cancer Chemoprevention, Chittaranjan National Cancer Institute (CNCI), 37, Shyama Prasad Mukherjee Rd, Bakul Bagan, Bhowanipore, Kolkata, West Bengal, 700026, India.
| |
Collapse
|
7
|
Bii VM, Rudoy D, Klezovitch O, Vasioukhin V. Lethal giant larvae gene family ( Llgl1 and Llgl2 ) functions as a tumor suppressor in mouse skin epidermis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531408. [PMID: 36945368 PMCID: PMC10028895 DOI: 10.1101/2023.03.06.531408] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Loss of cell polarity and tissue disorganization occurs in majority of epithelial cancers. Studies in simple model organisms identified molecular mechanisms responsible for the establishment and maintenance of cellular polarity, which play a pivotal role in establishing proper tissue architecture. The exact role of these cell polarity pathways in mammalian cancer is not completely understood. Here we analyzed the mammalian orthologs of drosophila apical-basal polarity gene lethal giant larvae ( lgl ), which regulates asymmetric stem cell division and functions as a tumor suppressor in flies. There are two mammalian orthologs of lgl ( Llgl1 and Llgl2 ). To determine the role of the entire lgl signaling pathway in mammals we generated mice with ablation of both Llgl1 and Llgl2 in skin epidermis using K14-Cre ( Llgl1/2 -/- cKO mice). Surprisingly, we found that ablation of Llgl1/2 genes does not impact epidermal polarity in adult mice. However, old Llgl1/2 cKO mice present with focal skin lesions which are missing epidermal layer and ripe with inflammation. To determine the role of lgl signaling pathway in cancer we generated Trp53 -/- /Llgl1/2 -/- cKO and Trp53 -/+ /Llgl1/2 -/- cKO mice. Loss of Llgl1/2 promoted squamous cell carcinoma (SCC) development in Trp53 -/- cKO and caused SCC in Trp53 -/+ cKO mice, while no cancer was observed in Trp53 -/+ cKO controls. Mechanistically, we show that ablation of Llgl1/2 causes activation of aPKC and upregulation of NF-kB signaling pathway, which may be necessary for SCC in Trp53 -/+ /Llgl1/2 -/- cKO mice. We conclude that Lgl signaling pathway functions as a tumor suppressor in mammalian skin epidermis.
Collapse
|
8
|
The Roles of Par3, Par6, and aPKC Polarity Proteins in Normal Neurodevelopment and in Neurodegenerative and Neuropsychiatric Disorders. J Neurosci 2022; 42:4774-4793. [PMID: 35705493 DOI: 10.1523/jneurosci.0059-22.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/30/2022] [Accepted: 05/02/2022] [Indexed: 11/21/2022] Open
Abstract
Normal neural circuits and functions depend on proper neuronal differentiation, migration, synaptic plasticity, and maintenance. Abnormalities in these processes underlie various neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Neural development and maintenance are regulated by many proteins. Among them are Par3, Par6 (partitioning defective 3 and 6), and aPKC (atypical protein kinase C) families of evolutionarily conserved polarity proteins. These proteins perform versatile functions by forming tripartite or other combinations of protein complexes, which hereafter are collectively referred to as "Par complexes." In this review, we summarize the major findings on their biophysical and biochemical properties in cell polarization and signaling pathways. We next summarize their expression and localization in the nervous system as well as their versatile functions in various aspects of neurodevelopment, including neuroepithelial polarity, neurogenesis, neuronal migration, neurite differentiation, synaptic plasticity, and memory. These versatile functions rely on the fundamental roles of Par complexes in cell polarity in distinct cellular contexts. We also discuss how cell polarization may correlate with subcellular polarization in neurons. Finally, we review the involvement of Par complexes in neuropsychiatric and neurodegenerative disorders, such as schizophrenia and Alzheimer's disease. While emerging evidence indicates that Par complexes are essential for proper neural development and maintenance, many questions on their in vivo functions have yet to be answered. Thus, Par3, Par6, and aPKC continue to be important research topics to advance neuroscience.
Collapse
|
9
|
Ma R, Gong D, You H, Xu C, Lu Y, Bergers G, Werb Z, Klein OD, Petritsch CK, Lu P. LGL1 binds to Integrin β1 and inhibits downstream signaling to promote epithelial branching in the mammary gland. Cell Rep 2022; 38:110375. [PMID: 35172155 PMCID: PMC9113222 DOI: 10.1016/j.celrep.2022.110375] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/08/2021] [Accepted: 01/20/2022] [Indexed: 11/29/2022] Open
Abstract
Branching morphogenesis is a fundamental process by which organs in invertebrates and vertebrates form branches to expand their surface areas. The current dogma holds that directional cell migration determines where a new branch forms and thus patterns branching. Here, we asked whether mouse Lgl1, a homolog of the Drosophila tumor suppressor Lgl, regulates epithelial polarity in the mammary gland. Surprisingly, mammary glands lacking Lgl1 have normal epithelial polarity, but they form fewer branches. Moreover, we find that Lgl1 null epithelium is unable to directionally migrate, suggesting that migration is not essential for mammary epithelial branching as expected. We show that LGL1 binds to Integrin β1 and inhibits its downstream signaling, and Integrin β1 overexpression blocks epithelial migration, thus recapitulating the Lgl1 null phenotype. Altogether, we demonstrate that Lgl1 modulation of Integrin β1 signaling is essential for directional migration and that epithelial branching in invertebrates and the mammary gland is fundamentally distinct. Ma et al. show that Lgl1 is essential for mammary gland branching morphogenesis but not epithelial polarity. Lgl1 is required for directional migration by regulating Integrin β1 signaling levels and focal adhesion strengths. Finally, branching mechanisms are distinct between mammary gland and Drosophila systems where directional migration is indispensable.
Collapse
Affiliation(s)
- Rongze Ma
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Difei Gong
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Huanyang You
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Chongshen Xu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yunzhe Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Gabriele Bergers
- VIB-KU Leuven Center for Cancer Biology, Department of Oncology, KU Leuven, 3000 Leuven, Belgium
| | - Zena Werb
- Department of Anatomy and Program in Developmental and Stem Cell Biology, University of California, San Francisco, San Francisco, CA 94143-0452, USA
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, UCSF Box 0422, 513 Parnassus Avenue, HSE1508, San Francisco, CA 94143-0422, USA
| | - Claudia K Petritsch
- Department of Neurological Surgery, Stanford University, Palo Alto, CA 94305, USA
| | - Pengfei Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| |
Collapse
|
10
|
Deng Q, Wang H. Re-visiting the principles of apicobasal polarity in Drosophila neural stem cells. Dev Biol 2022; 484:57-62. [PMID: 35181298 DOI: 10.1016/j.ydbio.2022.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/19/2022] [Accepted: 02/13/2022] [Indexed: 11/18/2022]
Abstract
The ability of stem cells to divide asymmetrically is crucial for cell-type diversity and tissue homeostasis. Drosophila neural stem cells, also knowns as neuroblasts, utilize asymmetric cell division to self-renew and give rise to differentiated daughter cells. Drosophila neuroblasts relies on the polarized protein complexes on the apical and basal cortex to govern cell polarity and asymmetry. Here, we review recent advances in our understanding of the neuroblast polarity focusing on how actin cytoskeleton, phosphoinositide lipids and liquid-liquid phase separation regulate the asymmetric cell division of Drosophila neuroblasts.
Collapse
Affiliation(s)
- Qiannan Deng
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Hongyan Wang
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Dept. of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore; Integrative Sciences and Engineering Programme, National University of Singapore, 28 Medical Drive, 117456, Singapore.
| |
Collapse
|
11
|
Doerflinger H, Zimyanin V, St Johnston D. The Drosophila anterior-posterior axis is polarized by asymmetric myosin activation. Curr Biol 2022; 32:374-385.e4. [PMID: 34856125 PMCID: PMC8791603 DOI: 10.1016/j.cub.2021.11.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 10/11/2021] [Accepted: 11/10/2021] [Indexed: 11/29/2022]
Abstract
The Drosophila anterior-posterior axis is specified at mid-oogenesis when the Par-1 kinase is recruited to the posterior cortex of the oocyte, where it polarizes the microtubule cytoskeleton to define where the axis determinants, bicoid and oskar mRNAs, localize. This polarity is established in response to an unknown signal from the follicle cells, but how this occurs is unclear. Here we show that the myosin chaperone Unc-45 and non-muscle myosin II (MyoII) are required upstream of Par-1 in polarity establishment. Furthermore, the myosin regulatory light chain (MRLC) is di-phosphorylated at the oocyte posterior in response to the follicle cell signal, inducing longer pulses of myosin contractility at the posterior that may increase cortical tension. Overexpression of MRLC-T21A that cannot be di-phosphorylated or treatment with the myosin light-chain kinase inhibitor ML-7 abolishes Par-1 localization, indicating that the posterior of MRLC di-phosphorylation is essential for both polarity establishment and maintenance. Thus, asymmetric myosin activation polarizes the anterior-posterior axis by recruiting and maintaining Par-1 at the posterior cortex. This raises an intriguing parallel with anterior-posterior axis formation in C. elegans, where MyoII also acts upstream of the PAR proteins to establish polarity, but to localize the anterior PAR proteins rather than Par-1.
Collapse
Affiliation(s)
- Hélène Doerflinger
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Vitaly Zimyanin
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Daniel St Johnston
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
| |
Collapse
|
12
|
Li Q, Jang H, Lim KY, Lessing A, Stavropoulos N. insomniac links the development and function of a sleep-regulatory circuit. eLife 2021; 10:65437. [PMID: 34908527 PMCID: PMC8758140 DOI: 10.7554/elife.65437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Although many genes are known to influence sleep, when and how they impact sleep-regulatory circuits remain ill-defined. Here, we show that insomniac (inc), a conserved adaptor for the autism-associated Cul3 ubiquitin ligase, acts in a restricted period of neuronal development to impact sleep in adult Drosophila. The loss of inc causes structural and functional alterations within the mushroom body (MB), a center for sensory integration, associative learning, and sleep regulation. In inc mutants, MB neurons are produced in excess, develop anatomical defects that impede circuit assembly, and are unable to promote sleep when activated in adulthood. Our findings link neurogenesis and postmitotic development of sleep-regulatory neurons to their adult function and suggest that developmental perturbations of circuits that couple sensory inputs and sleep may underlie sleep dysfunction in neurodevelopmental disorders.
Collapse
Affiliation(s)
- Qiuling Li
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Hyunsoo Jang
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Kayla Y Lim
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Alexie Lessing
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
| | - Nicholas Stavropoulos
- Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of MedicineNew YorkUnited States
- Waksman Institute, Rutgers UniversityPiscatawayUnited States
| |
Collapse
|
13
|
Rajan A, Ostgaard CM, Lee CY. Regulation of Neural Stem Cell Competency and Commitment during Indirect Neurogenesis. Int J Mol Sci 2021; 22:12871. [PMID: 34884676 PMCID: PMC8657492 DOI: 10.3390/ijms222312871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022] Open
Abstract
Indirect neurogenesis, during which neural stem cells generate neurons through intermediate progenitors, drives the evolution of lissencephalic brains to gyrencephalic brains. The mechanisms that specify intermediate progenitor identity and that regulate stem cell competency to generate intermediate progenitors remain poorly understood despite their roles in indirect neurogenesis. Well-characterized lineage hierarchy and available powerful genetic tools for manipulating gene functions make fruit fly neural stem cell (neuroblast) lineages an excellent in vivo paradigm for investigating the mechanisms that regulate neurogenesis. Type II neuroblasts in fly larval brains repeatedly undergo asymmetric divisions to generate intermediate neural progenitors (INPs) that undergo limited proliferation to increase the number of neurons generated per stem cell division. Here, we review key regulatory genes and the mechanisms by which they promote the specification and generation of INPs, safeguarding the indirect generation of neurons during fly larval brain neurogenesis. Homologs of these regulators of INPs have been shown to play important roles in regulating brain development in vertebrates. Insight into the precise regulation of intermediate progenitors will likely improve our understanding of the control of indirect neurogenesis during brain development and brain evolution.
Collapse
Affiliation(s)
- Arjun Rajan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
| | - Cyrina M. Ostgaard
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Cheng-Yu Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (A.R.); (C.M.O.)
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Division of Genetic Medicine, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| |
Collapse
|
14
|
Ryniawec JM, Rogers GC. Centrosome instability: when good centrosomes go bad. Cell Mol Life Sci 2021; 78:6775-6795. [PMID: 34476544 PMCID: PMC8560572 DOI: 10.1007/s00018-021-03928-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 08/10/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
The centrosome is a tiny cytoplasmic organelle that organizes and constructs massive molecular machines to coordinate diverse cellular processes. Due to its many roles during both interphase and mitosis, maintaining centrosome homeostasis is essential to normal health and development. Centrosome instability, divergence from normal centrosome number and structure, is a common pathognomonic cellular state tightly associated with cancers and other genetic diseases. As novel connections are investigated linking the centrosome to disease, it is critical to understand the breadth of centrosome functions to inspire discovery. In this review, we provide an introduction to normal centrosome function and highlight recent discoveries that link centrosome instability to specific disease states.
Collapse
Affiliation(s)
- John M Ryniawec
- University of Arizona Cancer Center, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724, USA
| | - Gregory C Rogers
- University of Arizona Cancer Center, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724, USA.
| |
Collapse
|
15
|
Abstract
Cells are biochemically and morphologically polarized, which allows them to produce different cell shapes for various functions. Remarkably, some polarity protein complexes are asymmetrically recruited and concentrated on limited membrane regions, which is essential for the establishment and maintenance of diverse cell polarity. Though the components and mutual interactions within these protein complexes have been extensively investigated, how these proteins autonomously concentrate at local membranes and whether they have the same organization mechanism in the condensed assembly as that in aqueous solution remain elusive. A number of recent studies suggest that these highly concentrated polarity protein assemblies are membraneless biomolecular condensates which form through liquid-liquid phase separation (LLPS) of specific proteins. In this perspective, we summarize the LLPS-driven condensed protein assemblies found in asymmetric cell division, epithelial cell polarity, and neuronal synapse formation and function. These findings suggest that LLPS may be a general strategy for cells to achieve local condensation of specific proteins, thus establishing cell polarity.
Collapse
Affiliation(s)
- Heyang Wei
- Department of Neurosurgery, Huashan Hospital, the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Wenyu Wen
- Department of Neurosurgery, Huashan Hospital, the Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| |
Collapse
|
16
|
Abstract
AbstractIn the developing Drosophila CNS, two pools of neural stem cells, the symmetrically dividing progenitors in the neuroepithelium (NE) and the asymmetrically dividing neuroblasts (NBs) generate the majority of the neurons that make up the adult central nervous system (CNS). The generation of a correct sized brain depends on maintaining the fine balance between neural stem cell self-renewal and differentiation, which are regulated by cell-intrinsic and cell-extrinsic cues. In this review, we will discuss our current understanding of how self-renewal and differentiation are regulated in the two neural stem cell pools, and the consequences of the deregulation of these processes.
Collapse
Affiliation(s)
- Francesca Froldi
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
| | - Milán Szuperák
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
| | - Louise Y. Cheng
- Peter MacCallum Cancer Centre, East Melbourne, Victoria, 3002, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria, 3010, Australia
| |
Collapse
|
17
|
LaFoya B, Prehoda KE. Actin-dependent membrane polarization reveals the mechanical nature of the neuroblast polarity cycle. Cell Rep 2021; 35:109146. [PMID: 34010656 PMCID: PMC8174105 DOI: 10.1016/j.celrep.2021.109146] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/26/2021] [Accepted: 04/26/2021] [Indexed: 12/18/2022] Open
Abstract
The Par complex directs fate-determinant segregation from the apical membrane of asymmetrically dividing Drosophila neuroblasts. While the physical interactions that recruit the Par complex have been extensively studied, little is known about how the membrane itself behaves during polarization. We examined the membrane dynamics of neuroblasts and surrounding cells using a combination of super-resolution and time-lapse imaging, revealing cellular-scale movements of diverse membrane features during asymmetric division cycles. Membrane domains that are distributed across the neuroblast membrane in interphase become polarized in early mitosis, where they mediate formation of cortical patches of the Par protein atypical protein kinase C (aPKC). Membrane and protein polarity cycles are precisely synchronized and are generated by extensive actin-dependent forces that deform the surrounding tissue. In addition to suggesting a role for the membrane in asymmetric division, our results reveal the mechanical nature of the neuroblast polarity cycle. LaFoya and Prehoda examine the membrane dynamics of asymmetrically dividing Drosophila neuroblasts and discover that the membrane undergoes a polarity cycle. Their studies show that membrane and protein polarity is precisely correlated and that cellular-scale forces generated during the cycle significantly deform the surrounding tissue.
Collapse
Affiliation(s)
- Bryce LaFoya
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA
| | - Kenneth E Prehoda
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA.
| |
Collapse
|
18
|
Raz AA, Wurtzel O, Reddien PW. Planarian stem cells specify fate yet retain potency during the cell cycle. Cell Stem Cell 2021; 28:1307-1322.e5. [PMID: 33882291 DOI: 10.1016/j.stem.2021.03.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 01/08/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
Planarian whole-body regeneration is enabled by stem cells called neoblasts. At least some neoblasts are individually pluripotent. Neoblasts are also heterogeneous, with subpopulations of specialized neoblasts having different specified fates. Fate specification in neoblasts is regulated by fate-specific transcription factor (FSTF) expression. Here, we find that FSTF expression is common in neoblast S/G2/M cell-cycle phases but less common in G1. We find that specialized neoblasts can divide to produce progeny with asymmetric cell fates, suggesting that they could retain pluripotency. Furthermore, no known neoblast class was present in all neoblast colonies, suggesting that pluripotency is not the exclusive property of any known class. We tested this possibility with single-cell transplantations, which indicate that at least some specialized neoblasts are likely clonogenic. On the basis of these findings, we propose a model for neoblast pluripotency in which neoblasts can undergo specialization during the cell cycle without loss of potency.
Collapse
Affiliation(s)
- Amelie A Raz
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Omri Wurtzel
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| |
Collapse
|
19
|
Thompson BJ. Par-3 family proteins in cell polarity & adhesion. FEBS J 2021; 289:596-613. [PMID: 33565714 PMCID: PMC9290619 DOI: 10.1111/febs.15754] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/19/2021] [Accepted: 02/08/2021] [Indexed: 12/27/2022]
Abstract
The Par‐3/Baz family of polarity determinants is highly conserved across metazoans and includes C. elegans PAR‐3, Drosophila Bazooka (Baz), human Par‐3 (PARD3), and human Par‐3‐like (PARD3B). The C. elegans PAR‐3 protein localises to the anterior pole of asymmetrically dividing zygotes with cell division cycle 42 (CDC42), atypical protein kinase C (aPKC), and PAR‐6. The same C. elegans ‘PAR complex’ can also localise in an apical ring in epithelial cells. Drosophila Baz localises to the apical pole of asymmetrically dividing neuroblasts with Cdc42‐aPKC‐Par6, while in epithelial cells localises both in an apical ring with Cdc42‐aPKC‐Par6 and with E‐cadherin at adherens junctions. These apical and junctional localisations have become separated in human PARD3, which is strictly apical in many epithelia, and human PARD3B, which is strictly junctional in many epithelia. We discuss the molecular basis for this fundamental difference in localisation, as well as the possible functions of Par‐3/Baz family proteins as oligomeric clustering agents at the apical domain or at adherens junctions in epithelial stem cells. The evolution of Par‐3 family proteins into distinct apical PARD3 and junctional PARD3B orthologs coincides with the emergence of stratified squamous epithelia in vertebrates, where PARD3B, but not PARD3, is strongly expressed in basal layer stem cells – which lack a typical apical domain. We speculate that PARD3B may contribute to clustering of E‐cadherin, signalling from adherens junctions via Src family kinases or mitotic spindle orientation by adherens junctions in response to mechanical forces.
Collapse
Affiliation(s)
- Barry J Thompson
- ACRF Department of Cancer Biology & Therapeutics, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| |
Collapse
|
20
|
Chippalkatti R, Egger B, Suter B. Mms19 promotes spindle microtubule assembly in Drosophila neural stem cells. PLoS Genet 2020; 16:e1008913. [PMID: 33211700 PMCID: PMC7714366 DOI: 10.1371/journal.pgen.1008913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 12/03/2020] [Accepted: 10/13/2020] [Indexed: 01/27/2023] Open
Abstract
Mitotic divisions depend on the timely assembly and proper orientation of the mitotic spindle. Malfunctioning of these processes can considerably delay mitosis, thereby compromising tissue growth and homeostasis, and leading to chromosomal instability. Loss of functional Mms19 drastically affects the growth and development of mitotic tissues in Drosophila larvae and we now demonstrate that Mms19 is an important factor that promotes spindle and astral microtubule (MT) growth, and MT stability and bundling. Mms19 function is needed for the coordination of mitotic events and for the rapid progression through mitosis that is characteristic of neural stem cells. Surprisingly, Mms19 performs its mitotic activities through two different pathways. By stimulating the mitotic kinase cascade, it triggers the localization of the MT regulatory complex TACC/Msps (Transforming Acidic Coiled Coil/Minispindles, the homolog of human ch-TOG) to the centrosome. This activity of Mms19 can be rescued by stimulating the mitotic kinase cascade. However, other aspects of the Mms19 phenotypes cannot be rescued in this way, pointing to an additional mechanism of Mms19 action. We provide evidence that Mms19 binds directly to MTs and that this stimulates MT stability and bundling.
Collapse
Affiliation(s)
- Rohan Chippalkatti
- Cell Biology, University of Bern, Berne, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Berne, Switzerland
| | - Boris Egger
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Beat Suter
- Cell Biology, University of Bern, Berne, Switzerland
| |
Collapse
|
21
|
Link N, Bellen HJ. Using Drosophila to drive the diagnosis and understand the mechanisms of rare human diseases. Development 2020; 147:dev191411. [PMID: 32988995 PMCID: PMC7541339 DOI: 10.1242/dev.191411] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Next-generation sequencing has greatly accelerated the discovery of rare human genetic diseases. Nearly 45% of patients have variants associated with known diseases but the unsolved cases remain a conundrum. Moreover, causative mutations can be difficult to pinpoint because variants frequently map to genes with no previous disease associations and, often, only one or a few patients with variants in the same gene are identified. Model organisms, such as Drosophila, can help to identify and characterize these new disease-causing genes. Importantly, Drosophila allow quick and sophisticated genetic manipulations, permit functional testing of human variants, enable the characterization of pathogenic mechanisms and are amenable to drug tests. In this Spotlight, focusing on microcephaly as a case study, we highlight how studies of human genes in Drosophila have aided our understanding of human genetic disorders, allowing the identification of new genes in well-established signaling pathways.
Collapse
Affiliation(s)
- Nichole Link
- Howard Hughes Medical Institute, BCM, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics (MHG), BCM, Houston, TX, 77030, USA
- Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Hugo J Bellen
- Howard Hughes Medical Institute, BCM, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics (MHG), BCM, Houston, TX, 77030, USA
- Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| |
Collapse
|
22
|
Holly RW, Jones K, Prehoda KE. A Conserved PDZ-Binding Motif in aPKC Interacts with Par-3 and Mediates Cortical Polarity. Curr Biol 2020; 30:893-898.e5. [PMID: 32084408 DOI: 10.1016/j.cub.2019.12.055] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/20/2019] [Accepted: 12/18/2019] [Indexed: 10/25/2022]
Abstract
Par-3 regulates animal cell polarity by targeting the Par complex proteins Par-6 and atypical protein kinase C (aPKC) to specific cortical sites. Although numerous physical interactions between Par-3 and the Par complex have been identified [1-6], we discovered a novel interaction between Par-3's second PDZ domain and a highly conserved aPKC PDZ-binding motif (PBM) that is required in the context of the full-length, purified Par-6-aPKC complex. We also found that Par-3 is phosphorylated by the full Par complex and phosphorylation induces dissociation of the Par-3 phosphorylation site from aPKC's kinase domain but does not disrupt the Par-3 PDZ2-aPKC PBM interaction. In asymmetrically dividing Drosophila neuroblasts, the aPKC PBM is required for cortical targeting, consistent with its role in mediating a persistent interaction with Par-3. Our results define a physical connection that targets the Par complex to polarized sites on the cell membrane.
Collapse
Affiliation(s)
- Ryan W Holly
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, 1229 University of Oregon, Eugene, OR 97403, USA
| | - Kimberly Jones
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, 1229 University of Oregon, Eugene, OR 97403, USA
| | - Kenneth E Prehoda
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, 1229 University of Oregon, Eugene, OR 97403, USA.
| |
Collapse
|
23
|
Loyer N, Januschke J. Where does asymmetry come from? Illustrating principles of polarity and asymmetry establishment in Drosophila neuroblasts. Curr Opin Cell Biol 2020; 62:70-77. [DOI: 10.1016/j.ceb.2019.07.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 12/22/2022]
|
24
|
Arora P, Dongre S, Raman R, Sonawane M. Stepwise polarisation of developing bilayered epidermis is mediated by aPKC and E-cadherin in zebrafish. eLife 2020; 9:49064. [PMID: 31967543 PMCID: PMC6975926 DOI: 10.7554/elife.49064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 12/13/2019] [Indexed: 12/20/2022] Open
Abstract
The epidermis, a multilayered epithelium, surrounds and protects the vertebrate body. It develops from a bilayered epithelium formed of the outer periderm and underlying basal epidermis. How apicobasal polarity is established in the developing epidermis has remained poorly understood. We show that both the periderm and the basal epidermis exhibit polarised distribution of adherens junctions in zebrafish. aPKC, an apical polarity regulator, maintains the robustness of polarisation of E-cadherin- an adherens junction component- in the periderm. E-cadherin in one layer controls the localisation of E-cadherin in the second layer in a layer non-autonomous manner. Importantly, E-cadherin controls the localisation and levels of Lgl, a basolateral polarity regulator, in a layer autonomous as well non-autonomous manner. Since periderm formation from the enveloping layer precedes the formation of the basal epidermis, our analyses suggest that peridermal polarity, initiated by aPKC, is transduced in a stepwise manner by E-cadherin to the basal layer.
Collapse
Affiliation(s)
- Prateek Arora
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Shivali Dongre
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Renuka Raman
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Mahendra Sonawane
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| |
Collapse
|
25
|
Montcouquiol M, Kelley MW. Development and Patterning of the Cochlea: From Convergent Extension to Planar Polarity. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a033266. [PMID: 30617059 DOI: 10.1101/cshperspect.a033266] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Within the mammalian cochlea, sensory hair cells and supporting cells are aligned in curvilinear rows that extend along the length of the tonotopic axis. In addition, all of the cells within the epithelium are uniformly polarized across the orthogonal neural-abneural axis. Finally, each hair cell is intrinsically polarized as revealed by the presence of an asymmetrically shaped and apically localized stereociliary bundle. It has been known for some time that many of the developmental processes that regulate these patterning events are mediated, to some extent, by the core planar cell polarity (PCP) pathway. This article will review more recent work demonstrating how components of the PCP pathway interact with cytoskeletal motor proteins to regulate cochlear outgrowth. Finally, a signaling pathway originally identified for its role in asymmetric cell divisions has recently been shown to mediate several aspects of intrinsic hair cell polarity, including kinocilia migration, bundle shape, and elongation.
Collapse
Affiliation(s)
- Mireille Montcouquiol
- INSERM, Neurocentre Magendie, U1215, F-33077 Bordeaux, France.,University of Bordeaux, Neurocentre Magendie, U1215, F-33077 Bordeaux, France
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892
| |
Collapse
|
26
|
Link N, Chung H, Jolly A, Withers M, Tepe B, Arenkiel BR, Shah PS, Krogan NJ, Aydin H, Geckinli BB, Tos T, Isikay S, Tuysuz B, Mochida GH, Thomas AX, Clark RD, Mirzaa GM, Lupski JR, Bellen HJ. Mutations in ANKLE2, a ZIKA Virus Target, Disrupt an Asymmetric Cell Division Pathway in Drosophila Neuroblasts to Cause Microcephaly. Dev Cell 2019; 51:713-729.e6. [PMID: 31735666 DOI: 10.1016/j.devcel.2019.10.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/19/2019] [Accepted: 10/14/2019] [Indexed: 12/12/2022]
Abstract
The apical Par complex, which contains atypical protein kinase C (aPKC), Bazooka (Par-3), and Par-6, is required for establishing polarity during asymmetric division of neuroblasts in Drosophila, and its activity depends on L(2)gl. We show that loss of Ankle2, a protein associated with microcephaly in humans and known to interact with Zika protein NS4A, reduces brain volume in flies and impacts the function of the Par complex. Reducing Ankle2 levels disrupts endoplasmic reticulum (ER) and nuclear envelope morphology, releasing the kinase Ballchen-VRK1 into the cytosol. These defects are associated with reduced phosphorylation of aPKC, disruption of Par-complex localization, and spindle alignment defects. Importantly, removal of one copy of ballchen or l(2)gl suppresses Ankle2 mutant phenotypes and restores viability and brain size. Human mutational studies implicate the above-mentioned genes in microcephaly and motor neuron disease. We suggest that NS4A, ANKLE2, VRK1, and LLGL1 define a pathway impinging on asymmetric determinants of neural stem cell division.
Collapse
Affiliation(s)
- Nichole Link
- Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Hyunglok Chung
- Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Angad Jolly
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; MD/PhD Medical Scientist Training Program and MHG Graduate program, BCM, Houston, TX 77030, USA
| | - Marjorie Withers
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA
| | - Burak Tepe
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA
| | - Benjamin R Arenkiel
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA
| | - Priya S Shah
- Department of Chemical Engineering and Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA 95616, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biosciences, QB3, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hatip Aydin
- Center of Genetics Diagnosis, Zeynep Kamil Maternity and Children's Training and Research Hospital, Istanbul, Turkey
| | - Bilgen B Geckinli
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulay Tos
- Department of Medical Genetics, Dr. Sami Ulus Research and Training Hospital of Women's and Children's Health and Diseases, Ankara, Turkey
| | - Sedat Isikay
- Department of Physiotherapy and Rehabilitation, Hasan Kalyoncu University, School of Health Sciences, Gaziantep, Turkey
| | - Beyhan Tuysuz
- Department of Pediatrics, Istanbul University-Cerrahpasa, Medical Faculty, Istanbul, Turkey
| | - Ganesh H Mochida
- Division of Genetics and Genomics, Department of Pediatrics and Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ajay X Thomas
- Department of Pediatrics, Section of Neurology and Developmental Neuroscience, BCM, Houston, TX 77030, USA; Section of Child Neurology, Texas Children's Hospital, Houston, TX 77030, USA
| | - Robin D Clark
- Division of Medical Genetics, Department of Pediatrics, Loma Linda University Medical Center, Loma Linda, CA 92354, USA
| | - Ghayda M Mirzaa
- Department of Pediatrics, University of Washington, Seattle, WA 98195, USA; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98105, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Department of Pediatrics, BCM, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J Bellen
- Howard Hughes Medical Institute, BCM, Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; MD/PhD Medical Scientist Training Program and MHG Graduate program, BCM, Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA.
| |
Collapse
|
27
|
aPKC in neuronal differentiation, maturation and function. Neuronal Signal 2019; 3:NS20190019. [PMID: 32269838 PMCID: PMC7104321 DOI: 10.1042/ns20190019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 12/17/2022] Open
Abstract
The atypical Protein Kinase Cs (aPKCs)—PRKCI, PRKCZ and PKMζ—form a subfamily within the Protein Kinase C (PKC) family. These kinases are expressed in the nervous system, including during its development and in adulthood. One of the aPKCs, PKMζ, appears to be restricted to the nervous system. aPKCs are known to play a role in a variety of cellular responses such as proliferation, differentiation, polarity, migration, survival and key metabolic functions such as glucose uptake, that are critical for nervous system development and function. Therefore, these kinases have garnered a lot of interest in terms of their functional role in the nervous system. Here we review the expression and function of aPKCs in neural development and in neuronal maturation and function. Despite seemingly paradoxical findings with genetic deletion versus gene silencing approaches, we posit that aPKCs are likely candidates for regulating many important neurodevelopmental and neuronal functions, and may be associated with a number of human neuropsychiatric diseases.
Collapse
|
28
|
Choi J, Troyanovsky RB, Indra I, Mitchell BJ, Troyanovsky SM. Scribble, Erbin, and Lano redundantly regulate epithelial polarity and apical adhesion complex. J Cell Biol 2019; 218:2277-2293. [PMID: 31147384 PMCID: PMC6605793 DOI: 10.1083/jcb.201804201] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 11/05/2018] [Accepted: 05/10/2019] [Indexed: 12/22/2022] Open
Abstract
The basolateral protein Scribble (Scrib), a member of the LAP protein family, is essential for epithelial apicobasal polarity (ABP) in Drosophila However, a conserved function for this protein in mammals is unclear. Here we show that the crucial role for Scrib in ABP has remained obscure due to the compensatory function of two other LAP proteins, Erbin and Lano. A combined Scrib/Erbin/Lano knockout disorganizes the cell-cell junctions and the cytoskeleton. It also results in mislocalization of several apical (Par6, aPKC, and Pals1) and basolateral (Llgl1 and Llgl2) identity proteins. These defects can be rescued by the conserved "LU" region of these LAP proteins. Structure-function analysis of this region determined that the so-called LAPSDb domain is essential for basolateral targeting of these proteins, while the LAPSDa domain is essential for supporting the membrane basolateral identity and binding to Llgl. In contrast to the key role in Drosophila, mislocalization of Llgl proteins does not appear to be critical in the scrib ABP phenotype.
Collapse
Affiliation(s)
- Jongho Choi
- Department of Dermatology, Northwestern University, The Feinberg School of Medicine, Chicago, IL
| | - Regina B Troyanovsky
- Department of Dermatology, Northwestern University, The Feinberg School of Medicine, Chicago, IL
| | - Indrajyoti Indra
- Department of Dermatology, Northwestern University, The Feinberg School of Medicine, Chicago, IL
| | - Brian J Mitchell
- Department of Cell and Molecular Biology, The Feinberg School of Medicine, Chicago, IL
| | - Sergey M Troyanovsky
- Department of Dermatology, Northwestern University, The Feinberg School of Medicine, Chicago, IL
| |
Collapse
|
29
|
Oon CH, Prehoda KE. Asymmetric recruitment and actin-dependent cortical flows drive the neuroblast polarity cycle. eLife 2019; 8:45815. [PMID: 31066675 PMCID: PMC6524966 DOI: 10.7554/elife.45815] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/07/2019] [Indexed: 12/12/2022] Open
Abstract
During the asymmetric divisions of Drosophila neuroblasts, the Par polarity complex cycles between the cytoplasm and an apical cortical domain that restricts differentiation factors to the basal cortex. We used rapid imaging of the full cell volume to uncover the dynamic steps that underlie transitions between neuroblast polarity states. Initially, the Par proteins aPKC and Bazooka form discrete foci at the apical cortex. Foci grow into patches that together comprise a discontinuous, unorganized structure. Coordinated cortical flows that begin near metaphase and are dependent on the actin cytoskeleton rapidly transform the patches into a highly organized apical cap. At anaphase onset, the cap disassembles as the cortical flow reverses direction toward the emerging cleavage furrow. Following division, cortical patches dissipate into the cytoplasm allowing the neuroblast polarity cycle to begin again. Our work demonstrates how neuroblasts use asymmetric recruitment and cortical flows to dynamically polarize during asymmetric division cycles.
Collapse
Affiliation(s)
- Chet Huan Oon
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, United States
| | - Kenneth E Prehoda
- Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, United States
| |
Collapse
|
30
|
Casas-Tintó S, Ferrús A. Troponin-I mediates the localization of selected apico-basal cell polarity signaling proteins. J Cell Sci 2019; 132:jcs.225243. [PMID: 30872455 DOI: 10.1242/jcs.225243] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 03/04/2019] [Indexed: 12/13/2022] Open
Abstract
Beyond its role in muscle contraction, Drosophila Troponin I (TnI; also known as Wings up A) is expressed in epithelial cells where it controls proliferation. TnI traffics between nucleus and cytoplasm through a sumoylation-dependent mechanism. We address here the role of TnI in the cytoplasm. TnI accumulates apically in epidermal cells and neuroblasts. TnI co-immunoprecipitates with Bazooka (also known as Par3) and Discs large (Dlg1, hereafter Dlg), two apico-basal polarity components. TnI depletion causes Baz and Dlg mislocalization; by contrast, the basolateral localization of Scribbled is not altered. In neuroblasts, TnI contributes to the polar localization of Miranda, while non-polar Dlg localization is not affected. Vertebrate phosphoinositide 3-kinase (PI3K) contributes to the apico-basal polarity of epithelia, but we find that Drosophila PI3K depletion alters neither the apical localization of TnI or Bazooka, nor the basal localization of Dlg. Nevertheless, overexpressing PI3K prevents the defects seen upon TnI depletion. TnI loss-of-function disrupts cytoskeletal β-Catenin, E-Cadherin and γ-Tubulin, and causes an increase in DNA damage, as revealed by analyzing γH2Av. We have previously shown that TnI depletion leads to apoptosis that can be suppressed by upregulating Sparc or downregulating Dronc. However, TnI-depleted cells expressing Sparc or downregulating Dronc, as well as those expressing p35 (also known as Cdk5α), that do not undergo apoptosis, still show DNA damage. This indicates that DNA damage is mechanistically independent of apoptosis induction. Thus, TnI binds certain apico-basal polarity signaling proteins in a cell type-dependent context, and this unveils a previously unsuspected diversity of mechanisms to allocate cell polarity factors.
Collapse
Affiliation(s)
- Sergio Casas-Tintó
- Department of Molecular, Cellular and Developmental Neurobiology, Instituto Cajal, C.S.I.C., Ave. Dr. Arce 37, Madrid 28002, Spain
| | - Alberto Ferrús
- Department of Molecular, Cellular and Developmental Neurobiology, Instituto Cajal, C.S.I.C., Ave. Dr. Arce 37, Madrid 28002, Spain
| |
Collapse
|
31
|
Hannaford M, Loyer N, Tonelli F, Zoltner M, Januschke J. A chemical-genetics approach to study the role of atypical Protein Kinase C in Drosophila. Development 2019; 146:dev170589. [PMID: 30635282 PMCID: PMC6361133 DOI: 10.1242/dev.170589] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022]
Abstract
Studying the function of proteins using genetics in cycling cells is complicated by the fact that there is often a delay between gene inactivation and the time point of phenotypic analysis. This is particularly true when studying kinases that have pleiotropic functions and multiple substrates. Drosophila neuroblasts (NBs) are rapidly dividing stem cells and an important model system for the study of cell polarity. Mutations in multiple kinases cause NB polarity defects, but their precise functions at particular time points in the cell cycle are unknown. Here, we use chemical genetics and report the generation of an analogue-sensitive allele of Drosophila atypical Protein Kinase C (aPKC). We demonstrate that the resulting mutant aPKC kinase can be specifically inhibited in vitro and in vivo Acute inhibition of aPKC during NB polarity establishment abolishes asymmetric localization of Miranda, whereas its inhibition during NB polarity maintenance does not in the time frame of normal mitosis. However, aPKC helps to sharpen the pattern of Miranda, by keeping it off the apical and lateral cortex after nuclear envelope breakdown.
Collapse
Affiliation(s)
- Matthew Hannaford
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Nicolas Loyer
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Francesca Tonelli
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Martin Zoltner
- Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| | - Jens Januschke
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD5 1EH, UK
| |
Collapse
|
32
|
aPKC controls endothelial growth by modulating c-Myc via FoxO1 DNA-binding ability. Nat Commun 2018; 9:5357. [PMID: 30559384 PMCID: PMC6297234 DOI: 10.1038/s41467-018-07739-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023] Open
Abstract
Strict regulation of proliferation is vital for development, whereas unregulated cell proliferation is a fundamental characteristic of cancer. The polarity protein atypical protein kinase C lambda/iota (aPKCλ) is associated with cell proliferation through unknown mechanisms. In endothelial cells, suppression of aPKCλ impairs proliferation despite hyperactivated mitogenic signaling. Here we show that aPKCλ phosphorylates the DNA binding domain of forkhead box O1 (FoxO1) transcription factor, a gatekeeper of endothelial growth. Although mitogenic signaling excludes FoxO1 from the nucleus, consequently increasing c-Myc abundance and proliferation, aPKCλ controls c-Myc expression via FoxO1/miR-34c signaling without affecting its localization. We find this pathway is strongly activated in the malignant vascular sarcoma, angiosarcoma, and aPKC inhibition reduces c-Myc expression and proliferation of angiosarcoma cells. Moreover, FoxO1 phosphorylation at Ser218 and aPKC expression correlates with poor patient prognosis. Our findings may provide a potential therapeutic strategy for treatment of malignant cancers, like angiosarcoma. The cell polarity regulator aPKC is associated with cell proliferation but the precise mechanism are unknown. Here, the authors find that aPKC lambda phosphorylates the FoxO1 transcription factor, a gatekeeper of endothelial growth, during both angiogenesis and angiosarcomas.
Collapse
|
33
|
Loyer N, Januschke J. The last-born daughter cell contributes to division orientation of Drosophila larval neuroblasts. Nat Commun 2018; 9:3745. [PMID: 30218051 PMCID: PMC6138640 DOI: 10.1038/s41467-018-06276-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 08/17/2018] [Indexed: 01/27/2023] Open
Abstract
Controlling the orientation of cell division is important in the context of cell fate choices and tissue morphogenesis. However, the mechanisms providing the required positional information remain incompletely understood. Here we use stem cells of the Drosophila larval brain that stably maintain their axis of polarity and division between cell cycles to identify cues that orient cell division. Using live cell imaging of cultured brains, laser ablation and genetics, we reveal that division axis maintenance relies on their last-born daughter cell. We propose that, in addition to known intrinsic cues, stem cells in the developing fly brain are polarized by an extrinsic signal. We further find that division axis maintenance allows neuroblasts to maximize their contact area with glial cells known to provide protective and proliferative signals to neuroblasts.
Collapse
Affiliation(s)
- Nicolas Loyer
- Cell & Developmental Biology, School of Life Sciences, University of Dundee, MSI/WTB3 Complex, Dow Street, Dundee, DD1 5EH, UK
| | - Jens Januschke
- Cell & Developmental Biology, School of Life Sciences, University of Dundee, MSI/WTB3 Complex, Dow Street, Dundee, DD1 5EH, UK.
| |
Collapse
|
34
|
Kullmann L, Krahn MP. Redundant regulation of localization and protein stability of DmPar3. Cell Mol Life Sci 2018; 75:3269-3282. [PMID: 29523893 PMCID: PMC11105499 DOI: 10.1007/s00018-018-2792-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 03/03/2018] [Accepted: 03/07/2018] [Indexed: 11/25/2022]
Abstract
Apical-basal polarity is an important characteristic of epithelia and Drosophila neural stem cells. The conserved Par complex, which consists of the atypical protein kinase C and the scaffold proteins Baz and Par6, is a key player in the establishment of apical-basal cell polarity. Membrane recruitment of Baz has been reported to be accomplished by several mechanisms, which might function in redundancy, to ensure the correct localization of the complex. However, none of the described interactions was sufficient to displace the protein from the apical junctions. Here, we dissected the role of the oligomerization domain and the lipid-binding motif of Baz in vivo in the Drosophila embryo. We found that these domains function in redundancy to ensure the apical junctional localization of Baz: inactivation of only one domain is not sufficient to disrupt the function of Baz during apical-basal polarization of epithelial cells and neural stem cells. In contrast, mutation of both domains results in a strongly impaired protein stability and a phenotype characterized by embryonic lethality and an impaired apical-basal polarity in the embryonic epithelium and neural stem cells, resembling a baz-loss of function allele. Strikingly, the binding of Baz to the transmembrane proteins E-Cadherin, Echinoid, and Starry Night was not affected in this mutant protein. Our findings reveal a redundant function of the oligomerization and the lipid-binding domain, which is required for protein stability, correct subcellular localization, and apical-basal cell polarization.
Collapse
Affiliation(s)
- Lars Kullmann
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
- Internal Medicine D, University Hospital of Münster, Domagkstr. 3a, 48149, Münster, Germany
| | - Michael P Krahn
- Molecular and Cellular Anatomy, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
- Internal Medicine D, University Hospital of Münster, Domagkstr. 3a, 48149, Münster, Germany.
| |
Collapse
|
35
|
Drosophila nucleostemin 3 is required to maintain larval neuroblast proliferation. Dev Biol 2018; 440:1-12. [PMID: 29679561 PMCID: PMC6278609 DOI: 10.1016/j.ydbio.2018.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 02/03/2023]
Abstract
Stem cells must maintain proliferation during tissue development, repair and homeostasis, yet avoid tumor formation. In Drosophila, neural stem cells (neuroblasts) maintain proliferation during embryonic and larval development and terminate cell cycle during metamorphosis. An important question for understanding how tissues are generated and maintained is: what regulates stem cell proliferation versus differentiation? We performed a genetic screen which identified nucleostemin 3 (ns3) as a gene required to maintain neuroblast proliferation. ns3 is evolutionarily conserved with yeast and human Lsg1, which encode putative GTPases and are essential for organism growth and viability. We found NS3 is cytoplasmic and it is required to retain the cell cycle repressor Prospero in neuroblast cytoplasm via a Ran-independent pathway. NS3 is also required for proper neuroblast cell polarity and asymmetric cell division. Structure-function analysis further shows that the GTP-binding domain and acidic domain are required for NS3 function in neuroblast proliferation. We conclude NS3 has novel roles in regulating neuroblast cell polarity and proliferation.
Collapse
|
36
|
Rust K, Tiwari MD, Mishra VK, Grawe F, Wodarz A. Myc and the Tip60 chromatin remodeling complex control neuroblast maintenance and polarity in Drosophila. EMBO J 2018; 37:embj.201798659. [PMID: 29997178 DOI: 10.15252/embj.201798659] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 02/04/2023] Open
Abstract
Stem cells establish cortical polarity and divide asymmetrically to simultaneously maintain themselves and generate differentiating offspring cells. Several chromatin modifiers have been identified as stemness factors in mammalian pluripotent stem cells, but whether these factors control stem cell polarity and asymmetric division has not been investigated so far. We addressed this question in Drosophila neural stem cells called neuroblasts. We identified the Tip60 chromatin remodeling complex and its interaction partner Myc as regulators of genes required for neuroblast maintenance. Knockdown of Tip60 complex members results in loss of cortical polarity, symmetric neuroblast division, and premature differentiation through nuclear entry of the transcription factor Prospero. We found that aPKC is the key target gene of Myc and the Tip60 complex subunit Domino in regulating neuroblast polarity. Our transcriptome analysis further showed that Domino regulates the expression of mitotic spindle genes previously identified as direct Myc targets. Our findings reveal an evolutionarily conserved functional link between Myc, the Tip60 complex, and the molecular network controlling cell polarity and asymmetric cell division.
Collapse
Affiliation(s)
- Katja Rust
- Molecular Cell Biology, Institute I for Anatomy, University of Cologne Medical School, Cologne, Germany .,Cluster of Excellence-Cellular Stress Response in Aging-Associated Diseases (CECAD), Cologne, Germany.,Stem Cell Biology, Institute for Anatomy and Cell Biology, Georg-August University Göttingen, Göttingen, Germany.,Department of Anatomy and OB-GYN/RS, University of California, San Francisco, San Francisco, CA, USA
| | - Manu D Tiwari
- Molecular Cell Biology, Institute I for Anatomy, University of Cologne Medical School, Cologne, Germany.,Cluster of Excellence-Cellular Stress Response in Aging-Associated Diseases (CECAD), Cologne, Germany.,Stem Cell Biology, Institute for Anatomy and Cell Biology, Georg-August University Göttingen, Göttingen, Germany
| | - Vivek Kumar Mishra
- Department of Dermatology and the Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
| | - Ferdi Grawe
- Molecular Cell Biology, Institute I for Anatomy, University of Cologne Medical School, Cologne, Germany
| | - Andreas Wodarz
- Molecular Cell Biology, Institute I for Anatomy, University of Cologne Medical School, Cologne, Germany .,Cluster of Excellence-Cellular Stress Response in Aging-Associated Diseases (CECAD), Cologne, Germany.,Stem Cell Biology, Institute for Anatomy and Cell Biology, Georg-August University Göttingen, Göttingen, Germany
| |
Collapse
|
37
|
Serrate/Notch Signaling Regulates the Size of the Progenitor Cell Pool in Drosophila Imaginal Rings. Genetics 2018; 209:829-843. [PMID: 29773559 DOI: 10.1534/genetics.118.300963] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/16/2018] [Indexed: 12/20/2022] Open
Abstract
Drosophila imaginal rings are larval tissues composed of progenitor cells that are essential for the formation of adult foreguts, hindguts, and salivary glands. Specified from subsets of ectoderm in the embryo, imaginal ring cells are kept quiescent until midsecond larval instar, and undergo rapid proliferation during the third instar to attain adequate numbers of cells that will replace apoptotic larval tissues for adult organ formation. Here, we show that Notch signaling is activated in all three imaginal rings from middle embryonic stage to early pupal stage, and that Notch signaling positively controls cell proliferation in all three imaginal rings during the third larval instar. Our mutant clonal analysis, knockdown, and gain-of-function studies indicate that canonical Notch pathway components are involved in regulating the proliferation of these progenitor cells. Both trans-activation and cis-inhibition between the ligand and receptor control Notch activation in the imaginal ring. Serrate (Ser) is the ligand provided from neighboring imaginal ring cells that trans-activates Notch signaling, whereas both Ser and Delta (Dl) could cis-inhibit Notch activity when the ligand and the receptor are in the same cell. In addition, we show that Notch signaling expressed in middle embryonic and first larval stages is required for the initial size of imaginal rings. Taken together, these findings indicate that imaginal rings are excellent in vivo models to decipher how progenitor cell number and proliferation are developmentally regulated, and that Notch signaling in these imaginal tissues is the primary growth-promoting signal that controls the size of the progenitor cell pool.
Collapse
|
38
|
Abstract
The Hippo signal transduction pathway is an important regulator of organ growth and cell differentiation, and its deregulation contributes to the development of cancer. The activity of the Hippo pathway is strongly dependent on cell junctions, cellular architecture, and the mechanical properties of the microenvironment. In this review, we discuss recent advances in our understanding of how cell junctions transduce signals from the microenvironment and control the activity of the Hippo pathway. We also discuss how these mechanisms may control organ growth during development and regeneration, and how defects in them deregulate Hippo signaling in cancer cells.
Collapse
Affiliation(s)
- Ruchan Karaman
- VIB Center for Cancer Biology, University of Leuven, 3000 Leuven, Belgium.,Department of Oncology, University of Leuven, 3000 Leuven, Belgium
| | - Georg Halder
- VIB Center for Cancer Biology, University of Leuven, 3000 Leuven, Belgium.,Department of Oncology, University of Leuven, 3000 Leuven, Belgium
| |
Collapse
|
39
|
Saito Y, Desai RR, Muthuswamy SK. Reinterpreting polarity and cancer: The changing landscape from tumor suppression to tumor promotion. Biochim Biophys Acta Rev Cancer 2018; 1869:103-116. [DOI: 10.1016/j.bbcan.2017.12.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022]
|
40
|
Koe CT, Tan YS, Lönnfors M, Hur SK, Low CSL, Zhang Y, Kanchanawong P, Bankaitis VA, Wang H. Vibrator and PI4KIIIα govern neuroblast polarity by anchoring non-muscle myosin II. eLife 2018; 7:33555. [PMID: 29482721 PMCID: PMC5828666 DOI: 10.7554/elife.33555] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/26/2018] [Indexed: 12/19/2022] Open
Abstract
A central feature of most stem cells is the ability to self-renew and undergo differentiation via asymmetric division. However, during asymmetric division the role of phosphatidylinositol (PI) lipids and their regulators is not well established. Here, we show that the sole type I PI transfer protein, Vibrator, controls asymmetric division of Drosophilaneural stem cells (NSCs) by physically anchoring myosin II regulatory light chain, Sqh, to the NSC cortex. Depletion of vib or disruption of its lipid binding and transfer activities disrupts NSC polarity. We propose that Vib stimulates PI4KIIIα to promote synthesis of a plasma membrane pool of phosphatidylinositol 4-phosphate [PI(4)P] that, in turn, binds and anchors myosin to the NSC cortex. Remarkably, Sqh also binds to PI(4)P in vitro and both Vib and Sqh mediate plasma membrane localization of PI(4)P in NSCs. Thus, reciprocal regulation between Myosin and PI(4)P likely governs asymmetric division of NSCs. Stem cells are cells that can both make copies of themselves and make new cells of various types. They can either divide symmetrically to produce two identical new cells, or they can divide asymmetrically to produce two different cells. Asymmetric division happens because the two new cells contain different molecules. Stem cells drive asymmetric division by moving key molecules to one end of the cell before they divide. Asymmetric division is key to how neural stem cells produce new brain cells. Many studies have used the developing brain of the fruit fly Drosophila melanogaster to understand this process. Errors in asymmetric division can lead to too many stem cells or not enough brain cells. This can contribute to brain tumors and other neurological disorders. Fat molecules called phosphatidylinositol lipids are some of chemicals that cause asymmetry in neural stem cells. Yet, it is not clear how these lipid molecules affect cell behavior to turn stem cells into brain cells. The production of phosphatidylinositol lipids involves proteins called Vibrator and PI4KIIIα. Koe et al. examined the role of these two proteins in asymmetric cell division of neural stem cells in fruit flies. The results show that Vibrator activates PI4KIIIα, which leads to high levels of a phosphatidylinositol lipid called PI(4)P within the cell. These lipids act as an anchor for a group of proteins called myosin, part of the machinery that physically divides the cell. Hence, myosin and phosphatidylinositol lipids together control asymmetric division of neural stem cells. Further experiments used mouse proteins to compensate for defects in the equivalent fly proteins. The results suggest that the same mechanisms are likely to hold true in mammalian brains, although this still needs to be proven. Nevertheless, given that human equivalents of Vibrator and PI4KIIIα are associated with neurodegenerative disorders, schizophrenia or cancers, these new findings are likely to help scientists better to understand several human diseases.
Collapse
Affiliation(s)
- Chwee Tat Koe
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Ye Sing Tan
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Max Lönnfors
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, United States
| | - Seong Kwon Hur
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, United States
| | | | - Yingjie Zhang
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore
| | - Pakorn Kanchanawong
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore.,Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Vytas A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, United States
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| |
Collapse
|
41
|
Abeysundara N, Simmonds AJ, Hughes SC. Moesin is involved in polarity maintenance and cortical remodeling during asymmetric cell division. Mol Biol Cell 2018; 29:419-434. [PMID: 29282284 PMCID: PMC6014166 DOI: 10.1091/mbc.e17-05-0294] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 12/08/2017] [Accepted: 12/13/2017] [Indexed: 01/17/2023] Open
Abstract
An intact actomyosin network is essential for anchoring polarity proteins to the cell cortex and maintaining cell size asymmetry during asymmetric cell division of Drosophila neuroblasts (NBs). However, the mechanisms that control changes in actomyosin dynamics during asymmetric cell division remain unclear. We find that the actin-binding protein, Moesin, is essential for NB proliferation and mitotic progression in the developing brain. During metaphase, phosphorylated Moesin (p-Moesin) is enriched at the apical cortex, and loss of Moesin leads to defects in apical polarity maintenance and cortical stability. This asymmetric distribution of p-Moesin is determined by components of the apical polarity complex and Slik kinase. During later stages of mitosis, p-Moesin localization shifts more basally, contributing to asymmetric cortical extension and myosin basal furrow positioning. Our findings reveal Moesin as a novel apical polarity protein that drives cortical remodeling of dividing NBs, which is essential for polarity maintenance and initial establishment of cell size asymmetry.
Collapse
Affiliation(s)
- Namal Abeysundara
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Andrew J Simmonds
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Sarah C Hughes
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada
| |
Collapse
|
42
|
Aguilar-Aragon M, Elbediwy A, Foglizzo V, Fletcher GC, Li VSW, Thompson BJ. Pak1 Kinase Maintains Apical Membrane Identity in Epithelia. Cell Rep 2018; 22:1639-1646. [PMID: 29444419 PMCID: PMC5847184 DOI: 10.1016/j.celrep.2018.01.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 12/14/2017] [Accepted: 01/18/2018] [Indexed: 01/03/2023] Open
Abstract
Epithelial cells are polarized along their apical-basal axis by the action of the small GTPase Cdc42, which is known to activate the aPKC kinase at the apical domain. However, loss of aPKC kinase activity was reported to have only mild effects on epithelial cell polarity. Here, we show that Cdc42 also activates a second kinase, Pak1, to specify apical domain identity in Drosophila and mammalian epithelia. aPKC and Pak1 phosphorylate an overlapping set of polarity substrates in kinase assays. Inactivating both aPKC kinase activity and the Pak1 kinase leads to a complete loss of epithelial polarity and morphology, with cells losing markers of apical polarization such as Crumbs, Par3/Bazooka, or ZO-1. This function of Pak1 downstream of Cdc42 is distinct from its role in regulating integrins or E-cadherin. Our results define a conserved dual-kinase mechanism for the control of apical membrane identity in epithelia.
Collapse
Affiliation(s)
| | - Ahmed Elbediwy
- Epithelial Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Valentina Foglizzo
- Stem Cell and Cancer Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Georgina C Fletcher
- Epithelial Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Vivian S W Li
- Stem Cell and Cancer Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
| | - Barry J Thompson
- Epithelial Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK.
| |
Collapse
|
43
|
Stephens R, Lim K, Portela M, Kvansakul M, Humbert PO, Richardson HE. The Scribble Cell Polarity Module in the Regulation of Cell Signaling in Tissue Development and Tumorigenesis. J Mol Biol 2018; 430:3585-3612. [PMID: 29409995 DOI: 10.1016/j.jmb.2018.01.011] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 01/22/2023]
Abstract
The Scribble cell polarity module, comprising Scribbled (Scrib), Discs-large (Dlg) and Lethal-2-giant larvae (Lgl), has a tumor suppressive role in mammalian epithelial cancers. The Scribble module proteins play key functions in the establishment and maintenance of different modes of cell polarity, as well as in the control of tissue growth, differentiation and directed cell migration, and therefore are major regulators of tissue development and homeostasis. Whilst molecular details are known regarding the roles of Scribble module proteins in cell polarity regulation, their precise mode of action in the regulation of other key cellular processes remains enigmatic. An accumulating body of evidence indicates that Scribble module proteins play scaffolding roles in the control of various signaling pathways, which are linked to the control of tissue growth, differentiation and cell migration. Multiple Scrib, Dlg and Lgl interacting proteins have been discovered, which are involved in diverse processes, however many function in the regulation of cellular signaling. Herein, we review the components of the Scrib, Dlg and Lgl protein interactomes, and focus on the mechanism by which they regulate cellular signaling pathways in metazoans, and how their disruption leads to cancer.
Collapse
Affiliation(s)
- Rebecca Stephens
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Krystle Lim
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Marta Portela
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute (CSIC), Avenida Doctor Arce, 37, Madrid 28002, Spain
| | - Marc Kvansakul
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Patrick O Humbert
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Anatomy & Neurobiology, University of Melbourne, Melbourne, Victoria 3010, Australia.
| |
Collapse
|
44
|
Hannaford MR, Ramat A, Loyer N, Januschke J. aPKC-mediated displacement and actomyosin-mediated retention polarize Miranda in Drosophila neuroblasts. eLife 2018; 7:29939. [PMID: 29364113 PMCID: PMC5783611 DOI: 10.7554/elife.29939] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/14/2018] [Indexed: 02/07/2023] Open
Abstract
Cell fate assignment in the nervous system of vertebrates and invertebrates often hinges on the unequal distribution of molecules during progenitor cell division. We address asymmetric fate determinant localization in the developing Drosophila nervous system, specifically the control of the polarized distribution of the cell fate adapter protein Miranda. We reveal a step-wise polarization of Miranda in larval neuroblasts and find that Miranda’s dynamics and cortical association are differently regulated between interphase and mitosis. In interphase, Miranda binds to the plasma membrane. Then, before nuclear envelope breakdown, Miranda is phosphorylated by aPKC and displaced into the cytoplasm. This clearance is necessary for the subsequent establishment of asymmetric Miranda localization. After nuclear envelope breakdown, actomyosin activity is required to maintain Miranda asymmetry. Therefore, phosphorylation by aPKC and differential binding to the actomyosin network are required at distinct phases of the cell cycle to polarize fate determinant localization in neuroblasts.
Collapse
Affiliation(s)
- Matthew Robert Hannaford
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Anne Ramat
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nicolas Loyer
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jens Januschke
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| |
Collapse
|
45
|
Carmena A. Compromising asymmetric stem cell division in Drosophila central brain: Revisiting the connections with tumorigenesis. Fly (Austin) 2018; 12:71-80. [PMID: 29239688 DOI: 10.1080/19336934.2017.1416277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Asymmetric cell division (ACD) is an essential process during development for generating cell diversity. In addition, a more recent connection between ACD, cancer and stem cell biology has opened novel and highly intriguing venues in the field. This connection between compromised ACD and tumorigenesis was first demonstrated using Drosophila neural stem cells (neuroblasts, NBs) more than a decade ago and, over the past years, it has also been established in vertebrate stem cells. Here, focusing on Drosophila larval brain NBs, and in light of results recently obtained in our lab, we revisit this connection emphasizing two main aspects: 1) the differences in tumor suppressor activity of different ACD regulators and 2) the potential relevance of environment and temporal window frame for compromised ACD-dependent induction of tumor-like overgrowth.
Collapse
Affiliation(s)
- Ana Carmena
- a Departamento de Neurobiología del Desarrollo , Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas/Universidad Miguel Hernández, Sant Joan d'Alacant , Alicante , Spain
| |
Collapse
|
46
|
Ramat A, Hannaford M, Januschke J. Maintenance of Miranda Localization in Drosophila Neuroblasts Involves Interaction with the Cognate mRNA. Curr Biol 2017; 27:2101-2111.e5. [PMID: 28690114 PMCID: PMC5526833 DOI: 10.1016/j.cub.2017.06.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/01/2017] [Accepted: 06/07/2017] [Indexed: 11/28/2022]
Abstract
How cells position their proteins is a key problem in cell biology. Targeting mRNAs to distinct regions of the cytoplasm contributes to protein localization by providing local control over translation. Here, we reveal that an interdependence of a protein and cognate mRNA maintains asymmetric protein distribution in mitotic Drosophila neural stem cells. We tagged endogenous mRNA or protein products of the gene miranda that is required for fate determination with GFP. We find that the mRNA localizes like the protein it encodes in a basal crescent in mitosis. We then used GFP-specific nanobodies fused to localization domains to alter the subcellular distribution of the GFP-tagged mRNA or protein. Altering the localization of the mRNA resulted in mislocalization of the protein and vice versa. Protein localization defects caused by mislocalization of the cognate mRNA were rescued by introducing untagged mRNA coding for mutant non-localizable protein. Therefore, by combining the MS2 system and subcellular nanobody expression, we uncovered that maintenance of Mira asymmetric localization requires interaction with the cognate mRNA.
Collapse
Affiliation(s)
- Anne Ramat
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK
| | - Matthew Hannaford
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK
| | - Jens Januschke
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK.
| |
Collapse
|
47
|
Sallé J, Gervais L, Boumard B, Stefanutti M, Siudeja K, Bardin AJ. Intrinsic regulation of enteroendocrine fate by Numb. EMBO J 2017; 36:1928-1945. [PMID: 28533229 DOI: 10.15252/embj.201695622] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 12/25/2022] Open
Abstract
How terminal cell fates are specified in dynamically renewing adult tissues is not well understood. Here we explore terminal cell fate establishment during homeostasis using the enteroendocrine cells (EEs) of the adult Drosophila midgut as a paradigm. Our data argue against the existence of local feedback signals, and we identify Numb as an intrinsic regulator of EE fate. Our data further indicate that Numb, with alpha-adaptin, acts upstream or in parallel of known regulators of EE fate to limit Notch signaling, thereby facilitating EE fate acquisition. We find that Numb is regulated in part through its asymmetric and symmetric distribution during stem cell divisions; however, its de novo synthesis is also required during the differentiation of the EE cell. Thus, this work identifies Numb as a crucial factor for cell fate choice in the adult Drosophila intestine. Furthermore, our findings demonstrate that cell-intrinsic control mechanisms of terminal cell fate acquisition can result in a balanced tissue-wide production of terminally differentiated cell types.
Collapse
Affiliation(s)
- Jérémy Sallé
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Louis Gervais
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Benjamin Boumard
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France.,Département de Biologie, École Normale Supérieure de Lyon, Lyon, France
| | - Marine Stefanutti
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Katarzyna Siudeja
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France.,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| | - Allison J Bardin
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis Group, Paris, France .,Sorbonne Universités, UPMC Univ Paris 6, Paris, France
| |
Collapse
|
48
|
Eritano AS, Altamirano A, Beyeler S, Gaytan N, Velasquez M, Riggs B. The endoplasmic reticulum is partitioned asymmetrically during mitosis before cell fate selection in proneuronal cells in the early Drosophila embryo. Mol Biol Cell 2017; 28:1530-1538. [PMID: 28381427 PMCID: PMC5449151 DOI: 10.1091/mbc.e16-09-0690] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 03/28/2017] [Accepted: 03/28/2017] [Indexed: 11/19/2022] Open
Abstract
In the early Drosophila embryo, epithelial cells begin to adopt a cell fate. At gastrulation, there is an asymmetric partitioning of the endoplasmic reticulum in a symmetrically dividing cell population before cell fate selection. These results highlight the changes in organelle distribution before asymmetric divisions. Asymmetric cell division is the primary mechanism to generate cellular diversity, and it relies on the correct partitioning of cell fate determinants. However, the mechanism by which these determinants are delivered and positioned is poorly understood, and the upstream signal to initiate asymmetric cell division is unknown. Here we report that the endoplasmic reticulum (ER) is asymmetrically partitioned during mitosis in epithelial cells just before delamination and selection of a proneural cell fate in the early Drosophila embryo. At the start of gastrulation, the ER divides asymmetrically into a population of asynchronously dividing cells at the anterior end of the embryo. We found that this asymmetric division of the ER depends on the highly conserved ER membrane protein Jagunal (Jagn). RNA inhibition of jagn just before the start of gastrulation disrupts this asymmetric division of the ER. In addition, jagn-deficient embryos display defects in apical-basal spindle orientation in delaminated embryonic neuroblasts. Our results describe a model in which an organelle is partitioned asymmetrically in an otherwise symmetrically dividing cell population just upstream of cell fate determination and updates previous models of spindle-based selection of cell fate during mitosis.
Collapse
Affiliation(s)
- Anthony S Eritano
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Arturo Altamirano
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sarah Beyeler
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Norma Gaytan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Mark Velasquez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| |
Collapse
|
49
|
Paglia S, Sollazzo M, Di Giacomo S, de Biase D, Pession A, Grifoni D. Failure of the PTEN/aPKC/Lgl Axis Primes Formation of Adult Brain Tumours in Drosophila. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2690187. [PMID: 29445734 PMCID: PMC5763105 DOI: 10.1155/2017/2690187] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/02/2017] [Accepted: 11/08/2017] [Indexed: 02/05/2023]
Abstract
Different regions in the mammalian adult brain contain immature precursors, reinforcing the concept that brain cancers, such as glioblastoma multiforme (GBM), may originate from cells endowed with stem-like properties. Alterations of the tumour suppressor gene PTEN are very common in primary GBMs. Very recently, PTEN loss was shown to undermine a specific molecular axis, whose failure is associated with the maintenance of the GBM stem cells in mammals. This axis is composed of PTEN, aPKC, and the polarity determinant Lethal giant larvae (Lgl): PTEN loss promotes aPKC activation through the PI3K pathway, which in turn leads to Lgl inhibition, ultimately preventing stem cell differentiation. To find the neural precursors responding to perturbations of this molecular axis, we targeted different neurogenic regions of the Drosophila brain. Here we show that PTEN mutation impacts aPKC and Lgl protein levels also in Drosophila. Moreover, we demonstrate that PI3K activation is not sufficient to trigger tumourigenesis, while aPKC promotes hyperplastic growth of the neuroepithelium and a noticeable expansion of the type II neuroblasts. Finally, we show that these neuroblasts form invasive tumours that persist and keep growing in the adult, leading the affected animals to untimely death, thus displaying frankly malignant behaviours.
Collapse
Affiliation(s)
- Simona Paglia
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Manuela Sollazzo
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Simone Di Giacomo
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Dario de Biase
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Annalisa Pession
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| | - Daniela Grifoni
- Department of “Pharmacy and Biotechnology”, University of Bologna, Via Selmi 3, 40126 Bologna, Italy
| |
Collapse
|
50
|
Regulation of Asymmetric Cell Division in Mammalian Neural Stem and Cancer Precursor Cells. Results Probl Cell Differ 2017; 61:375-399. [PMID: 28409314 DOI: 10.1007/978-3-319-53150-2_17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stem and progenitor cells are characterized by their abilities to self-renew and produce differentiated progeny. The balance between self-renewal and differentiation is achieved through control of cell division mode, which can be either asymmetric or symmetric. Failure to properly control cell division mode may result in premature depletion of the stem/progenitor cell pool or abnormal growth and impaired differentiation. In many tissues, including the brain, stem cells and progenitor cells undergo asymmetric cell division through the establishment of cell polarity. Cell polarity proteins are therefore potentially critical regulators of asymmetric cell division. Decrease or loss of asymmetric cell division can be associated with reduced differentiation common during aging or impaired remyelination as seen in demyelinating diseases. Progenitor-like glioma precursor cells show decreased asymmetric cell division rates and increased symmetric divisions, which suggests that asymmetric cell division suppresses brain tumor formation. Cancer stem cells, on the other hand, still undergo low rates of asymmetric cell division, which may provide them with a survival advantage during therapy. These findings led to the hypotheses that asymmetric cell divisions are not always tumor suppressive but can also be utilized to maintain a cancer stem cell population. Proper control of cell division mode is therefore not only deemed necessary to generate cellular diversity during development and to maintain adult tissue homeostasis but may also prevent disease and determine disease progression. Since brain cancer is most common in the adult and aging population, we review here the current knowledge on molecular mechanisms that regulate asymmetric cell divisions in the neural and oligodendroglial lineage during development and in the adult brain.
Collapse
|