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Chitre K, Kairamkonda S, Dwivedi MK, Yadav S, Kumar V, Sikdar SK, Nongthomba U. Beadex, the Drosophila LIM only protein, is required for the growth of the larval neuromuscular junction. J Neurophysiol 2024; 132:418-432. [PMID: 38838299 DOI: 10.1152/jn.00064.2024] [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: 02/12/2024] [Revised: 05/31/2024] [Accepted: 06/05/2024] [Indexed: 06/07/2024] Open
Abstract
The appropriate growth of the neurons, accurate organization of their synapses, and successful neurotransmission are indispensable for sensorimotor activities. These processes are highly dynamic and tightly regulated. Extensive genetic, molecular, physiological, and behavioral studies have identified many molecular candidates and investigated their roles in various neuromuscular processes. In this article, we show that Beadex (Bx), the Drosophila LIM only (LMO) protein, is required for motor activities and neuromuscular growth of Drosophila. The larvae bearing Bx7, a null allele of Bx, and the RNAi-mediated neuronal-specific knockdown of Bx show drastically reduced crawling behavior, a diminished synaptic span of the neuromuscular junctions (NMJs) and an increased spontaneous neuronal firing with altered motor patterns in the central pattern generators (CPGs). Microarray studies identified multiple targets of Beadex that are involved in different cellular and molecular pathways, including those associated with the cytoskeleton and mitochondria that could be responsible for the observed neuromuscular defects. With genetic interaction studies, we further show that Highwire (Hiw), a negative regulator of synaptic growth at the NMJs, negatively regulates Bx, as the latter's deficiency was able to rescue the phenotype of the Hiw null mutant, HiwDN. Thus, our data indicate that Beadex functions downstream of Hiw to regulate the larval synaptic growth and physiology.NEW & NOTEWORTHY A novel role for Beadex (Bx) regulates the larval neuromuscular junction (NMJ) structure and function in a tissue-specific manner. Bx is expressed in a subset of Toll-6-expressing neurons and is involved in regulating synaptic span and physiology, possibly through its negative interaction with Highwire (Hiw). The findings of this study provide insights into the molecular mechanisms underlying NMJ development and function and warrant further investigation to understand the role of Bx in these processes fully.
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Affiliation(s)
- Kripa Chitre
- Department of Development Biology and Genetics (DBG), Indian Institute of Science (IISc), Bangalore, India
| | - Subhash Kairamkonda
- Department of Development Biology and Genetics (DBG), Indian Institute of Science (IISc), Bangalore, India
| | - Manish Kumar Dwivedi
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India
| | - Saumitra Yadav
- Molecular Biophysics Unit (MBU), Indian Institute of Science (IISc), Bangalore, India
| | - Vimlesh Kumar
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India
| | - Sujit K Sikdar
- Molecular Biophysics Unit (MBU), Indian Institute of Science (IISc), Bangalore, India
| | - Upendra Nongthomba
- Department of Development Biology and Genetics (DBG), Indian Institute of Science (IISc), Bangalore, India
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Chatterjee A, Aavula K, Nongthomba U. Beadex, a homologue of the vertebrate LIM domain only protein, is a novel regulator of crystal cell development in Drosophila melanogaster. J Genet 2019; 98:107. [PMID: 31819023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Haematopoiesis is a complex process in which the regulatory mechanisms of several implicated transcription factors remain uncertain. Drosophila melanogaster is an excellent model to resolve the unanswered questions about the blood cell development. This study describes the role of Beadex, a Drosophila homologue of LIM domain only 2 (LMO2), in haematopoiesis. Mutants of Beadex were analysed for blood cell abnormalities. Crystal cells, a subset of haemocytes, were significantly more in Beadex hypermorphic flies. Similarly, Beadex misexpression in prohemocytes altered the crystal cell numbers. Stage-specific misexpression analyses demonstrated that Beadex functions after the prohemocytes enter the crystal cell lineage. We also discovered that Pannier-U-shaped complex is a negative regulator of the crystal cell differentiation and is possibly negatively regulated by Beadex through its interaction with Pannier. We, therefore, suggest the mechanism of two novel regulators of crystal cell specification-Beadex and Pannier-during Drosophila haematopoiesis.
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Affiliation(s)
- Arunita Chatterjee
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru 560 012, India.
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CHATTERJEE ARUNITA, AAVULA KUMAR, NONGTHOMBA UPENDRA. Beadex, a homologue of the vertebrate LIM domain only protein, is a novel regulator of crystal cell development in Drosophila melanogaster. J Genet 2019. [DOI: 10.1007/s12041-019-1154-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Furman DP, Bukharina TV. The bristle pattern development in Drosophila melanogaster: the prepattern and achaete-scute genes. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj18.449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- D. P. Furman
- Institute of Cytology and Genetics, SB RAS; Novosibirsk State University
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Kairamkonda S, Nongthomba U. Beadex, a Drosophila LIM domain only protein, function in follicle cells is essential for egg development and fertility. Exp Cell Res 2018; 367:97-103. [PMID: 29580687 DOI: 10.1016/j.yexcr.2018.03.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 11/25/2022]
Abstract
LIM domain, constituted by two tandem C2H2 zinc finger motif, proteins regulate several biological processes. They are usually found associated with various functional domains like Homeodomain, kinase domain and other protein binding domains. LIM proteins that are devoid of other domains are called LIM only proteins (LMO). LMO proteins were first identified in humans and are implicated in development and oncogenesis. They regulate various cell specifications by regulating the activity of respective transcriptional complexes. The Drosophila LMO protein (dLMO), Beadex (Bx), regulates various developmental processes like wing margin development and bristle development. It also regulates Drosophila behavior in response to cocaine and ethanol. We have previously generated Bx null flies and shown its essential function in neurons for multiple aspects of female reproduction. However, it was not known whether Bx affects reproduction through its independent function in ovaries. In this paper we show that female flies null for Bx lay eggs with multiple defects. Further, through knock down studies we demonstrate that function of Bx in follicle cells is required for normal egg development. We also show that function of Bx is particularly required in border cells for Drosophila fertility.
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Affiliation(s)
- Subhash Kairamkonda
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Upendra Nongthomba
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India.
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Kairamkonda S, Nongthomba U. Beadex function in the motor neurons is essential for female reproduction in Drosophila melanogaster. PLoS One 2014; 9:e113003. [PMID: 25396431 PMCID: PMC4232528 DOI: 10.1371/journal.pone.0113003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 10/17/2014] [Indexed: 01/08/2023] Open
Abstract
Drosophila melanogaster has served as an excellent model system for understanding the neuronal circuits and molecular mechanisms regulating complex behaviors. The Drosophila female reproductive circuits, in particular, are well studied and can be used as a tool to understand the role of novel genes in neuronal function in general and female reproduction in particular. In the present study, the role of Beadex, a transcription co-activator, in Drosophila female reproduction was assessed by generation of mutant and knock down studies. Null allele of Beadex was generated by transposase induced excision of P-element present within an intron of Beadex gene. The mutant showed highly compromised reproductive abilities as evaluated by reduced fecundity and fertility, abnormal oviposition and more importantly, the failure of sperm release from storage organs. However, no defect was found in the overall ovariole development. Tissue specific, targeted knock down of Beadex indicated that its function in neurons is important for efficient female reproduction, since its neuronal knock down led to compromised female reproductive abilities, similar to Beadex null females. Further, different neuronal class specific knock down studies revealed that Beadex function is required in motor neurons for normal fecundity and fertility of females. Thus, the present study attributes a novel and essential role for Beadex in female reproduction through neurons.
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Affiliation(s)
- Subhash Kairamkonda
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, India
- * E-mail:
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Hainaut M, Sagnier T, Berenger H, Pradel J, Graba Y, Miotto B. The MYST-containing protein Chameau is required for proper sensory organ specification during Drosophila thorax morphogenesis. PLoS One 2012; 7:e32882. [PMID: 22412942 PMCID: PMC3295779 DOI: 10.1371/journal.pone.0032882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 02/04/2012] [Indexed: 12/15/2022] Open
Abstract
The adult thorax of Drosophila melanogaster is covered by a stereotyped pattern of mechanosensory bristles called macrochaetes. Here, we report that the MYST containing protein Chameau (Chm) contributes to the establishment of this pattern in the most dorsal part of the thorax. Chm mutant pupae present extra-dorsocentral (DC) and scutellar (SC) macrochaetes, but a normal number of the other macrochaetes. We provide evidences that chm restricts the singling out of sensory organ precursors from proneural clusters and genetically interacts with transcriptional regulators involved in the regulation of achaete and scute in the DC and SC proneural cluster. This function of chm likely relies on chromatin structure regulation since a protein with a mutation in the conserved catalytic site fails to rescue the formation of supernumerary DC and SC bristles in chm mutant flies. This is further supported by the finding that mutations in genes encoding chromatin modifiers and remodeling factors, including Polycomb group (PcG) and Trithorax group (TrxG) members, dominantly modulate the penetrance of chm extra bristle phenotype. These data support a critical role for chromatin structure modulation in the establishment of the stereotyped sensory bristle pattern in the fly thorax.
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Affiliation(s)
- Matthieu Hainaut
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Thierry Sagnier
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Hélène Berenger
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Jacques Pradel
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Yacine Graba
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
- * E-mail: (YG); (BM)
| | - Benoit Miotto
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
- * E-mail: (YG); (BM)
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Asprer JST, Lee B, Wu CS, Vadakkan T, Dickinson ME, Lu HC, Lee SK. LMO4 functions as a co-activator of neurogenin 2 in the developing cortex. Development 2011; 138:2823-32. [PMID: 21652654 DOI: 10.1242/dev.061879] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The proneural protein neurogenin 2 (NGN2) is a key transcription factor in regulating both neurogenesis and neuronal radial migration in the embryonic cerebral cortex. However, the co-factors that support the action of NGN2 in the cortex remain unclear. Here, we show that the LIM-only protein LMO4 functions as a novel co-factor of NGN2 in the developing cortex. LMO4 and its binding partner nuclear LIM interactor (NLI/LDB1/CLIM2) interact with NGN2 simultaneously, forming a multi-protein transcription complex. This complex is recruited to the E-box containing enhancers of NGN2-target genes, which regulate various aspects of cortical development, and activates NGN2-mediated transcription. Correspondingly, analysis of Lmo4-null embryos shows that the loss of LMO4 leads to impairments of neuronal differentiation in the cortex. In addition, expression of LMO4 facilitates NGN2-mediated radial migration of cortical neurons in the embryonic cortex. Our results indicate that LMO4 promotes the acquisition of cortical neuronal identities by forming a complex with NGN2 and subsequently activating NGN2-dependent gene expression.
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Affiliation(s)
- Joanna S T Asprer
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Bronstein R, Segal D. Modularity of CHIP/LDB transcription complexes regulates cell differentiation. Fly (Austin) 2011; 5:200-5. [PMID: 21406967 DOI: 10.4161/fly.5.3.14854] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Transcription is the first step through which the cell operates, via its repertoire of transcription complexes, to direct cellular functions and cellular identity by generating the cell-specific transcriptome. The modularity of the composition of constituents of these complexes allows the cell to delicately regulate its transcriptome. In a recent study we have examined the effects of reducing the levels of specific transcription co-factors on the function of two competing transcription complexes, namely CHIP-AP and CHIP-PNR which regulate development of cells in the thorax of Drosophila. We found that changing the availability of these co-factors can shift the balance between these complexes leading to transition from utilization of CHIP-AP to CHIP-PNR. This is reflected in change in the expression profile of target genes, altering developmental cell fates. We propose that such a mechanism may operate in normal fly development. Transcription complexes analogous to CHIP-AP and CHIP-PNR exist in mammals and we discuss how such a shift in the balance between them may operate in normal mammalian development.
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Affiliation(s)
- Revital Bronstein
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
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Bronstein R, Levkovitz L, Yosef N, Yanku M, Ruppin E, Sharan R, Westphal H, Oliver B, Segal D. Transcriptional regulation by CHIP/LDB complexes. PLoS Genet 2010; 6:e1001063. [PMID: 20730086 PMCID: PMC2921152 DOI: 10.1371/journal.pgen.1001063] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Accepted: 07/12/2010] [Indexed: 01/18/2023] Open
Abstract
It is increasingly clear that transcription factors play versatile roles in turning genes "on" or "off" depending on cellular context via the various transcription complexes they form. This poses a major challenge in unraveling combinatorial transcription complex codes. Here we use the powerful genetics of Drosophila combined with microarray and bioinformatics analyses to tackle this challenge. The nuclear adaptor CHIP/LDB is a major developmental regulator capable of forming tissue-specific transcription complexes with various types of transcription factors and cofactors, making it a valuable model to study the intricacies of gene regulation. To date only few CHIP/LDB complexes target genes have been identified, and possible tissue-dependent crosstalk between these complexes has not been rigorously explored. SSDP proteins protect CHIP/LDB complexes from proteasome dependent degradation and are rate-limiting cofactors for these complexes. By using mutations in SSDP, we identified 189 down-stream targets of CHIP/LDB and show that these genes are enriched for the binding sites of APTEROUS (AP) and PANNIER (PNR), two well studied transcription factors associated with CHIP/LDB complexes. We performed extensive genetic screens and identified target genes that genetically interact with components of CHIP/LDB complexes in directing the development of the wings (28 genes) and thoracic bristles (23 genes). Moreover, by in vivo RNAi silencing we uncovered novel roles for two of the target genes, xbp1 and Gs-alpha, in early development of these structures. Taken together, our results suggest that loss of SSDP disrupts the normal balance between the CHIP-AP and the CHIP-PNR transcription complexes, resulting in down-regulation of CHIP-AP target genes and the concomitant up-regulation of CHIP-PNR target genes. Understanding the combinatorial nature of transcription complexes as presented here is crucial to the study of transcription regulation of gene batteries required for development.
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Affiliation(s)
- Revital Bronstein
- Department of Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Liron Levkovitz
- Department of Physiology and Pharmacology, Tel Aviv University, Tel Aviv, Israel
- Balvatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Nir Yosef
- Balvatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Michaela Yanku
- Department of Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Eytan Ruppin
- Department of Physiology and Pharmacology, Tel Aviv University, Tel Aviv, Israel
- Balvatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Roded Sharan
- Balvatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel
| | - Heiner Westphal
- Section on Mammalian Molecular Genetics, Program in Genomics of Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brian Oliver
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel Segal
- Department of Microbiology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
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