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Immunoprophylaxis using polypeptide chimera vaccines plus adjuvant system promote Th1 response controlling the spleen parasitism in hamster model of visceral leishmaniasis. Vaccine 2022; 40:5494-5503. [PMID: 35963820 DOI: 10.1016/j.vaccine.2022.08.005] [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: 03/24/2022] [Revised: 07/20/2022] [Accepted: 08/03/2022] [Indexed: 11/23/2022]
Abstract
In recent years, several advances have been observed in vaccinology especially for neglected tropical diseases (NTDs). One of the tools employed is epitope prediction by immunoinformatic approaches that reduce the time and cost to develop a vaccine. In this scenario, immunoinformatics is being more often used to develop vaccines for NTDs, in particular visceral leishmaniasis (VL) which is proven not to have an effective vaccine yet. Based on that, in a previous study, two predicted T-cell multi-epitope chimera vaccines were experimentally validated in BALB/c mice to evaluate the immunogenicity, central and effector memory and protection against VL. Considering the results obtained in the mouse model, we assessed the immune response of these chimeras inMesocricetus auratushamster, which displays, experimentally, similar pathological status to human and dog VL disease. Our findings indicate that both chimeras lead to a dominant Th1 response profile, inducing a strong cellular response by increasing the production of IFN-γ and TNF-α cytokines associated with a decrease in IL-10. Also, the chimeras reduced the spleen parasite load and the weight a correlation between protector immunological mechanisms and consistent reduction of the parasitic load was observed. Our results demonstrate that both chimeras were immunogenic and corroborate with findings in the mouse model. Therefore, we reinforce the use of the hamster as a pre-clinical model in vaccination trials for canine and human VL and the importance of immunoinformatic to identify epitopes to design vaccines for this important neglected disease.
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Characterization of paralogous uncx transcription factor encoding genes in zebrafish. Gene X 2019; 721S:100011. [PMID: 31193955 PMCID: PMC6543554 DOI: 10.1016/j.gene.2019.100011] [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: 07/27/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/23/2022] Open
Abstract
The paired-type homeodomain transcription factor Uncx is involved in multiple processes of embryogenesis in vertebrates. Reasoning that zebrafish genes uncx4.1 and uncx are orthologs of mouse Uncx, we studied their genomic environment and developmental expression. Evolutionary analyses indicate the zebrafish uncx genes as being paralogs deriving from teleost-specific whole-genome duplication. Whole-mount in situ mRNA hybridization of uncx transcripts in zebrafish embryos reveals novel expression domains, confirms those previously known, and suggests sub-functionalization of paralogs. Using genetic mutants and pharmacological inhibitors, we investigate the role of signaling pathways on the expression of zebrafish uncx genes in developing somites. In identifying putative functional role(s) of zebrafish uncx genes, we hypothesized that they encode transcription factors that coordinate growth and innervation of somitic muscles. The Uncx4.1 and Uncx genes derive from the teleost-specific whole-genome duplication. Uncx genes are expressed during embryogenesis in unique and overlapping domains. Uncx gene expression during somite differentiation is regulated by FGF signaling. Synteny and expression profiles correlate Uncx genes with axon guidance.
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Key Words
- AP, antero-posterior
- Ace, acerebellar
- CAMP, conserved ancestral microsyntenic pairs
- CNE, conserved non-coding elements
- CRM, cis-regulatory module
- CS, Corpuscle of Stannius
- CaP, caudal primary motor neuron axons
- Ce, cerebellum
- Development
- Di, diencephalon
- Elfn1, Extracellular Leucine Rich Repeat And Fibronectin Type III Domain Containing 1
- Ey, eye
- FB, forebrain
- FGF, fibroblast growth factor
- Flh, floating head
- HB, hindbrain
- HM, hybridization mix
- Hy, hypothalamus
- MO, morpholino
- Mical, molecule interacting with CasL
- No, notochord
- OP, olfactory placode
- OT, optic tectum
- PA, pharyngeal arches
- PSM, presomitic mesoderm
- SC, spinal cord
- Shh, sonic hedgehog
- Signaling pathway
- So, somites
- Synteny
- TSGD
- TSGD, teleost-specific genome duplication
- Te, telencephalon
- Th, thalamus
- Uncx
- VLP, ventro-lateral-posterior
- WIHC, whole-mount immunohistochemistry
- WISH, whole-mount in situ hybridization
- YE, yolk extension
- Yo, yolk
- Zebrafish
- cyc, cyclops
- fss, fused-somites
- hpf, hours post fertilization
- ptc, patched
- smu, slow-muscle-omitted
- syu, sonic-you
- yot, you-too
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Cai Y, Lu J, Tang F. Overexpression of MICAL2, a novel tumor-promoting factor, accelerates tumor progression through regulating cell proliferation and EMT. J Cancer 2018; 9:521-527. [PMID: 29483957 PMCID: PMC5820919 DOI: 10.7150/jca.22355] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 10/20/2017] [Indexed: 12/11/2022] Open
Abstract
Molecule interacting with CasL 2 (MICAL2), a microtubule associated monooxygenase, is involved in cell growth, axon guidance, vesicle trafficking and apoptosis. Recent studies have demonstrated that MICAL2 is highly expressed in tumor and accelerates tumor progression and it is deemed to be a novel tumor-promoting factor. MICAL2 overexpression increases cell proliferation to accelerate tumor growth, and MICAL2 also promotes epithelial-mesenchymal transition (EMT)-related proteins to increase cancer cell metastasis. On mechanism, MICAL2 induces EMT by regulating SRF (serum response factor)/MRTF-A (myocardin related transcription factor A) signaling, Semaphorin/Plexin pathway and inducing ROS (Reactive oxygen species) production. In the present review, we introduced MICAL family, expatiated the structure and functions of MICALs, and summarized the mechanisms of MICAL2 involving tumor progression. The challenges and perspectives for MICAL2 in tumor are also discussed.
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Affiliation(s)
- Yongqiang Cai
- Clinical Laboratory and Medical Research Center, Zhuhai Hospital, Jinan University, Zhuhai 519000, Guangdong, China
| | - Jinping Lu
- Clinical Laboratory and Medical Research Center, Zhuhai Hospital, Jinan University, Zhuhai 519000, Guangdong, China
| | - Faqing Tang
- Clinical Laboratory and Medical Research Center, Zhuhai Hospital, Jinan University, Zhuhai 519000, Guangdong, China
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4
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Atkinson-Leadbeater K, Hehr CL, Johnston J, Bertolesi G, McFarlane S. EGCG stabilizes growth cone filopodia and impairs retinal ganglion cell axon guidance. Dev Dyn 2016; 245:667-77. [DOI: 10.1002/dvdy.24406] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 03/05/2016] [Accepted: 03/12/2016] [Indexed: 12/14/2022] Open
Affiliation(s)
| | - Carrie L. Hehr
- Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary Alberta
| | - Jill Johnston
- Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary Alberta
| | - Gabriel Bertolesi
- Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary Alberta
| | - Sarah McFarlane
- Hotchkiss Brain Institute; Department of Cell Biology and Anatomy; University of Calgary; Calgary Alberta
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Giridharan SSP, Caplan S. MICAL-family proteins: Complex regulators of the actin cytoskeleton. Antioxid Redox Signal 2014; 20:2059-73. [PMID: 23834433 PMCID: PMC3993057 DOI: 10.1089/ars.2013.5487] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SIGNIFICANCE The molecules interacting with CasL (MICAL) family members participate in a multitude of activities, including axonal growth cone repulsion, membrane trafficking, apoptosis, and bristle development in flies. An interesting feature of MICAL proteins is the presence of an N-terminal flavo-mono-oxygenase domain. This mono-oxygenase domain generates redox potential with which MICALs can either oxidize proteins or produce reactive oxygen species (ROS). Actin is one such protein that is affected by MICAL function, leading to dramatic cytoskeletal rearrangements. This review describes the MICAL-family members, and discusses their mechanisms of actin-binding and regulation of actin cytoskeleton organization. RECENT ADVANCES Recent studies show that MICALs directly induce oxidation of actin molecules, leading to actin depolymerization. ROS production by MICALs also causes oxidation of collapsin response mediator protein-2, a microtubule assembly promoter, which subsequently undergoes phosphorylation. CRITICAL ISSUES MICAL proteins oxidize proteins through two mechanisms: either directly by oxidizing methionine residues or indirectly via the production of ROS. It remains unclear whether MICAL proteins employ both mechanisms or whether the activity of MICAL-family proteins might vary with different substrates. FUTURE DIRECTIONS The identification of additional substrates oxidized by MICAL will shed new light on MICAL protein function. Additional directions include expanding studies toward the MICAL-like homologs that lack flavin adenine dinucleotide domains and oxidation activity.
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Affiliation(s)
- Sai Srinivas Panapakkam Giridharan
- Department of Biochemistry and Molecular Biology, and the Pamela and Fred Buffett Cancer Center, University of Nebraska Medical Center , Omaha, Nebraska
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Carayannopoulos MO, Xiong F, Jensen P, Rios-Galdamez Y, Huang H, Lin S, Devaskar SU. GLUT3 gene expression is critical for embryonic growth, brain development and survival. Mol Genet Metab 2014; 111:477-83. [PMID: 24529979 PMCID: PMC4536922 DOI: 10.1016/j.ymgme.2014.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 01/25/2014] [Indexed: 01/05/2023]
Abstract
Glucose is the primary energy source for eukaryotic cells and the predominant substrate for the brain. GLUT3 is essential for trans-placental glucose transport and highly expressed in the mammalian brain. To further elucidate the role of GLUT3 in embryonic development, we utilized the vertebrate whole animal model system of Danio rerio as a tractable system for defining the cellular and molecular mechanisms altered by impaired glucose transport and metabolism related to perturbed expression of GLUT3. The comparable orthologue of human GLUT3 was identified and the expression of this gene abrogated during early embryonic development. In a dose-dependent manner embryonic brain development was disrupted resulting in a phenotype of aberrant brain organogenesis, associated with embryonic growth restriction and increased cellular apoptosis. Rescue of the morphant phenotype was achieved by providing exogenous GLUT3 mRNA. We conclude that GLUT3 is critically important for brain organogenesis and embryonic growth. Disruption of GLUT3 is responsible for the phenotypic spectrum of embryonic growth restriction to demise and neural apoptosis with microcephaly.
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Affiliation(s)
| | - Fuxia Xiong
- Department of Pediatrics, Division of Neonatology and Developmental Biology, Neonatal Research Center at the UCLA Children's Discovery & Innovation Institute, David Geffen School of Medicine UCLA, Los Angeles, CA, USA
| | - Penny Jensen
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Haigen Huang
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, USA
| | - Shuo Lin
- Department of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, USA
| | - Sherin U Devaskar
- Department of Pediatrics, Division of Neonatology and Developmental Biology, Neonatal Research Center at the UCLA Children's Discovery & Innovation Institute, David Geffen School of Medicine UCLA, Los Angeles, CA, USA.
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Lundquist MR, Storaska AJ, Liu TC, Larsen SD, Evans T, Neubig RR, Jaffrey SR. Redox modification of nuclear actin by MICAL-2 regulates SRF signaling. Cell 2014; 156:563-76. [PMID: 24440334 PMCID: PMC4384661 DOI: 10.1016/j.cell.2013.12.035] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 09/23/2013] [Accepted: 11/12/2013] [Indexed: 12/16/2022]
Abstract
The serum response factor (SRF) binds to coactivators, such as myocardin-related transcription factor-A (MRTF-A), and mediates gene transcription elicited by diverse signaling pathways. SRF/MRTF-A-dependent gene transcription is activated when nuclear MRTF-A levels increase, enabling the formation of transcriptionally active SRF/MRTF-A complexes. The level of nuclear MRTF-A is regulated by nuclear G-actin, which binds to MRTF-A and promotes its nuclear export. However, pathways that regulate nuclear actin levels are poorly understood. Here, we show that MICAL-2, an atypical actin-regulatory protein, mediates SRF/MRTF-A-dependent gene transcription elicited by nerve growth factor and serum. MICAL-2 induces redox-dependent depolymerization of nuclear actin, which decreases nuclear G-actin and increases MRTF-A in the nucleus. Furthermore, we show that MICAL-2 is a target of CCG-1423, a small molecule inhibitor of SRF/MRTF-A-dependent transcription that exhibits efficacy in various preclinical disease models. These data identify redox modification of nuclear actin as a regulatory switch that mediates SRF/MRTF-A-dependent gene transcription.
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Affiliation(s)
- Mark R Lundquist
- Department of Pharmacology, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - Andrew J Storaska
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ting-Chun Liu
- Department of Surgery, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - Scott D Larsen
- Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Todd Evans
- Department of Surgery, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - Richard R Neubig
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA.
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Xia Z, Tong X, Liang F, Zhang Y, Kuok C, Zhang Y, Liu X, Zhu Z, Lin S, Zhang B. Eif3ba regulates cranial neural crest development by modulating p53 in zebrafish. Dev Biol 2013; 381:83-96. [PMID: 23791820 DOI: 10.1016/j.ydbio.2013.06.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/01/2013] [Accepted: 06/06/2013] [Indexed: 02/05/2023]
Abstract
Congenital diseases caused by abnormal development of the cranial neural crest usually present craniofacial malformations and heart defects while the precise mechanism is not fully understood. Here, we show that the zebrafish eif3ba mutant caused by pseudo-typed retrovirus insertion exhibited a similar phenotype due to the hypogenesis of cranial neural crest cells (NCCs). The derivatives of cranial NCCs, including the NCC-derived cell population of pharyngeal arches, craniofacial cartilage, pigment cells and the myocardium derived from cardiac NCCs, were affected in this mutant. The expression of several neural crest marker genes, including crestin, dlx2a and nrp2b, was specifically reduced in the cranial regions of the eif3ba mutant. Through fluorescence-tracing of the cranial NCC migration marker nrp2b, we observed reduced intensity of NCC-derived cells in the heart. In addition, p53 was markedly up-regulated in the eif3ba mutant embryos, which correlated with pronounced apoptosis in the cranial area as shown by TUNEL staining. These findings suggest a novel function of eif3ba during embryonic development and a novel level of regulation in the process of cranial NCC development, in addition to providing a potential animal model to mimic congenital diseases due to cranial NCC defects. Furthermore, we report the identification of a novel transgenic fish line Et(gata2a:EGFP)pku418 to trace the migration of cranial NCCs (including cardiac NCCs); this may serve as an invaluable tool for investigating the development and dynamics of cranial NCCs during zebrafish embryogenesis.
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Affiliation(s)
- Zhidan Xia
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, PR China
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MICAL, the flavoenzyme participating in cytoskeleton dynamics. Int J Mol Sci 2013; 14:6920-59. [PMID: 23535333 PMCID: PMC3645671 DOI: 10.3390/ijms14046920] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/02/2013] [Accepted: 03/11/2013] [Indexed: 01/01/2023] Open
Abstract
MICAL (from the Molecule Interacting with CasL) indicates a family of recently discovered cytosolic, multidomain proteins, which uniquely couple an N-terminal FAD-containing monooxygenase-like domain to typical calponine homology, LIM and coiled-coil protein-interaction modules. Genetic and cell biology approaches have demonstrated an essential role of the catalytic activity of the monooxygenase-like domain in transducing the signal initiated by semaphorins interaction with their plexin receptors, which results in local actin cytoskeleton disassembly as part of fundamental processes that include differentiation, migration and cell-cell contacts in neuronal and non-neuronal cell types. This review focuses on the structure-function relations of the MICAL monooxygenase-like domain as they are emerging from the available in vitro studies on mouse, human and Drosophila MICAL forms that demonstrated a NADPH-dependent actin depolymerizing activity of MICAL. With Drosophila MICAL forms, actin depolymerization was demonstrated to be associated to conversion of Met44 to methionine sulfone through a postulated hydroxylating reaction. Arguments supporting the concept that MICAL effect on F-actin may be reversible will be discussed.
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10
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Huang P, Xu L, Liang W, Tam CI, Zhang Y, Qi F, Zhu Z, Lin S, Zhang B. Genomic deletion induced by Tol2 transposon excision in zebrafish. Nucleic Acids Res 2012; 41:e36. [PMID: 23143102 PMCID: PMC3553969 DOI: 10.1093/nar/gks1035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Genomic deletions induced by imprecise excision of transposons have been used to disrupt gene functions in Drosophila. To determine the excision properties of Tol2, a popular transposon in zebrafish, we took advantage of two transgenic zebrafish lines Et(gata2a:EGFP)pku684 and Et(gata2a:EGFP)pku760, and mobilized the transposon by injecting transposase mRNA into homozygous transgenic embryos. Footprint analysis showed that the Tol2 transposons were excised in either a precise or an imprecise manner. Furthermore, we identified 1093-bp and 1253-bp genomic deletions in Et(gata2a:EGFP)pku684 founder embryos flanking the 5′ end of the original Tol2 insertion site, and a 1340-bp deletion in the Et(gata2a:EGFP)pku760 founder embryos flanking the 3′ end of the insertion site. The mosaic Et(gata2a:EGFP)pku684 embryos were raised to adulthood and screened for germline transmission of Tol2 excision in their F1 progeny. On average, ∼42% of the F1 embryos displayed loss or altered EGFP patterns, demonstrating that this transposon could be efficiently excised from the zebrafish genome in the germline. Furthermore, from 59 founders, we identified one that transmitted the 1093-bp genomic deletion to its offspring. These results suggest that imprecise Tol2 transposon excision can be used as an alternative strategy to achieve gene targeting in zebrafish.
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Affiliation(s)
- Peng Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, PR China
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11
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Zhou Y, Gunput RAF, Adolfs Y, Pasterkamp RJ. MICALs in control of the cytoskeleton, exocytosis, and cell death. Cell Mol Life Sci 2011; 68:4033-44. [PMID: 21822644 PMCID: PMC3221843 DOI: 10.1007/s00018-011-0787-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 07/14/2011] [Accepted: 07/19/2011] [Indexed: 12/19/2022]
Abstract
MICALs form an evolutionary conserved family of multidomain signal transduction proteins characterized by a flavoprotein monooxygenase domain. MICALs are being implicated in the regulation of an increasing number of molecular and cellular processes including cytoskeletal dynamics and intracellular trafficking. Intriguingly, some of these effects are dependent on the MICAL monooxygenase enzyme and redox signaling, while other functions rely on other parts of the MICAL protein. Recent breakthroughs in our understanding of MICAL signaling identify the ability of MICALs to bind and directly modify the actin cytoskeleton, link MICALs to the docking and fusion of exocytotic vesicles, and uncover MICALs as anti-apoptotic proteins. These discoveries could lead to therapeutic advances in neural regeneration, cancer, and other diseases.
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Affiliation(s)
- Yeping Zhou
- Department of Neuroscience and Pharmacology, University Medical Center Utrecht, STR 4.229, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Rou-Afza F. Gunput
- Department of Neuroscience and Pharmacology, University Medical Center Utrecht, STR 4.229, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Youri Adolfs
- Department of Neuroscience and Pharmacology, University Medical Center Utrecht, STR 4.229, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - R. Jeroen Pasterkamp
- Department of Neuroscience and Pharmacology, University Medical Center Utrecht, STR 4.229, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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Hung RJ, Terman JR. Extracellular inhibitors, repellents, and semaphorin/plexin/MICAL-mediated actin filament disassembly. Cytoskeleton (Hoboken) 2011; 68:415-33. [PMID: 21800438 PMCID: PMC3612987 DOI: 10.1002/cm.20527] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Accepted: 07/21/2011] [Indexed: 01/29/2023]
Abstract
Multiple extracellular signals have been identified that regulate actin dynamics within motile cells, but how these instructive cues present on the cell surface exert their precise effects on the internal actin cytoskeleton is still poorly understood. One particularly interesting class of these cues is a group of extracellular proteins that negatively alter the movement of cells and their processes. Over the years, these types of events have been described using a variety of terms and herein we provide an overview of inhibitory/repulsive cellular phenomena and highlight the largest known protein family of repulsive extracellular cues, the Semaphorins. Specifically, the Semaphorins (Semas) utilize Plexin cell-surface receptors to dramatically collapse the actin cytoskeleton and we summarize what is known of the direct molecular and biochemical mechanisms of Sema-triggered actin filament (F-actin) disassembly. We also discuss new observations from our lab that reveal that the multidomain oxidoreductase (Redox) enzyme Molecule Interacting with CasL (MICAL), an important mediator of Sema/Plexin repulsion, is a novel F-actin disassembly factor. Our results indicate that MICAL triggers Sema/Plexin-mediated reorganization of the F-actin cytoskeleton and suggest a role for specific Redox signaling events in regulating actin dynamics.
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Affiliation(s)
- Ruei-Jiun Hung
- Departments of Neuroscience and Pharmacology, and Neuroscience Graduate Program, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R. Terman
- Departments of Neuroscience and Pharmacology, and Neuroscience Graduate Program, Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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