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Borkúti P, Kristó I, Szabó A, Kovács Z, Vilmos P. FERM domain-containing proteins are active components of the cell nucleus. Life Sci Alliance 2024; 7:e202302489. [PMID: 38296350 PMCID: PMC10830384 DOI: 10.26508/lsa.202302489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/05/2024] Open
Abstract
The FERM domain is a conserved and widespread protein module that appeared in the common ancestor of amoebae, fungi, and animals, and is therefore now found in a wide variety of species. The primary function of the FERM domain is localizing to the plasma membrane through binding lipids and proteins of the membrane; thus, for a long time, FERM domain-containing proteins (FDCPs) were considered exclusively cytoskeletal. Although their role in the cytoplasm has been extensively studied, the recent discovery of the presence and importance of cytoskeletal proteins in the nucleus suggests that FDCPs might also play an important role in nuclear function. In this review, we collected data on their nuclear localization, transport, and possible functions, which are still scattered throughout the literature, with special regard to the role of the FERM domain in these processes. With this, we would like to draw attention to the exciting, new dimension of the role of FDCPs, their nuclear activity, which could be an interesting novel direction for future research.
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Affiliation(s)
| | | | - Anikó Szabó
- HUN-REN Biological Research Centre, Szeged, Hungary
| | - Zoltán Kovács
- HUN-REN Biological Research Centre, Szeged, Hungary
- Doctoral School of Multidisciplinary Medical Science, University of Szeged, Szeged, Hungary
| | - Péter Vilmos
- HUN-REN Biological Research Centre, Szeged, Hungary
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2
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Huang SC, Vu LV, Yu FH, Nguyen DT, Benz EJ. Multifunctional protein 4.1R regulates the asymmetric segregation of Numb during terminal erythroid maturation. J Biol Chem 2021; 297:101051. [PMID: 34364872 PMCID: PMC8408529 DOI: 10.1016/j.jbc.2021.101051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 10/25/2022] Open
Abstract
The asymmetric cell division of stem or progenitor cells generates daughter cells with distinct fates that balance proliferation and differentiation. Asymmetric segregation of Notch signaling regulatory protein Numb plays a crucial role in cell diversification. However, the molecular mechanism remains unclear. Here, we examined the unequal distribution of Numb in the daughter cells of murine erythroleukemia cells (MELCs) that undergo DMSO-induced erythroid differentiation. In contrast to the cytoplasmic localization of Numb during uninduced cell division, Numb is concentrated at the cell boundary in interphase, near the one-spindle pole in metaphase, and is unequally distributed to one daughter cell in anaphase in induced cells. The inheritance of Numb guides this daughter cell toward erythroid differentiation while the other cell remains a progenitor cell. Mitotic spindle orientation, critical for distribution of cell fate determinants, requires complex communication between the spindle microtubules and the cell cortex mediated by the NuMA-LGN-dynein/dynactin complex. Depletion of each individual member of the complex randomizes the position of Numb relative to the mitotic spindle. Gene replacement confirms that multifunctional erythrocyte protein 4.1R (4.1R) functions as a member of the NuMA-LGN-dynein/dynactin complex and is necessary for regulating spindle orientation, in which interaction between 4.1R and NuMA plays an important role. These results suggest that mispositioning of Numb is the result of spindle misorientation. Finally, disruption of the 4.1R-NuMA-LGN complex increases Notch signaling and decreases the erythroblast population. Together, our results identify a critical role for 4.1R in regulating the asymmetric segregation of Numb to mediate erythropoiesis.
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Affiliation(s)
- Shu-Ching Huang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA; Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA; Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
| | - Long V Vu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Faye H Yu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Dan T Nguyen
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Edward J Benz
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA; Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA; Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA; Department of Pediatrics and Genetics, Harvard Medical School, Boston, Massachusetts, USA; Leukemia Program, Dana-Farber/Harvard Cancer Center, Boston, Massachusetts, USA
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3
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Huang SC, Liang JY, Vu LV, Yu FH, Ou AC, Ou JP, Zhang HS, Burnett KM, Benz EJ. Epithelial-specific isoforms of protein 4.1R promote adherens junction assembly in maturing epithelia. J Biol Chem 2020; 295:191-211. [PMID: 31776189 PMCID: PMC6952607 DOI: 10.1074/jbc.ra119.009650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/20/2019] [Indexed: 01/13/2023] Open
Abstract
Epithelial adherens junctions (AJs) and tight junctions (TJs) undergo disassembly and reassembly during morphogenesis and pathological states. The membrane-cytoskeleton interface plays a crucial role in junctional reorganization. Protein 4.1R (4.1R), expressed as a diverse array of spliceoforms, has been implicated in linking the AJ and TJ complex to the cytoskeleton. However, which specific 4.1 isoform(s) participate and the mechanisms involved in junctional stability or remodeling remain unclear. We now describe a role for epithelial-specific isoforms containing exon 17b and excluding exon 16 4.1R (4.1R+17b) in AJs. 4.1R+17b is exclusively co-localized with the AJs. 4.1R+17b binds to the armadillo repeats 1-2 of β-catenin via its membrane-binding domain. This complex is linked to the actin cytoskeleton via a bispecific interaction with an exon 17b-encoded peptide. Exon 17b peptides also promote fodrin-actin complex formation. Expression of 4.1R+17b forms does not disrupt the junctional cytoskeleton and AJs during the steady-state or calcium-dependent AJ reassembly. Overexpression of 4.1R-17b forms, which displace the endogenous 4.1R+17b forms at the AJs, as well as depletion of the 4.1R+17b forms both decrease junctional actin and attenuate the recruitment of spectrin to the AJs and also reduce E-cadherin during the initial junctional formation of the AJ reassembly process. Expressing 4.1R+17b forms in depleted cells rescues junctional localization of actin, spectrin, and E-cadherin assembly at the AJs. Together, our results identify a critical role for 4.1R+17b forms in AJ assembly and offer additional insights into the spectrin-actin-4.1R-based membrane skeleton as an emerging regulator of epithelial integrity and remodeling.
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Affiliation(s)
- Shu-Ching Huang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115; Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115; Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
| | - Jia Y Liang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Long V Vu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Faye H Yu
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Alexander C Ou
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Jennie Park Ou
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Henry S Zhang
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Kimberly M Burnett
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Edward J Benz
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115; Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115; Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115; Department of Pediatrics and Genetics, Harvard Medical School, Boston, Massachusetts 02115; Dana-Farber/Harvard Cancer Center, Boston, Massachusetts 02115
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Bazzini C, Benedetti L, Civello D, Zanoni C, Rossetti V, Marchesi D, Garavaglia ML, Paulmichl M, Francolini M, Meyer G, Rodighiero S. ICln: a new regulator of non-erythroid 4.1R localisation and function. PLoS One 2014; 9:e108826. [PMID: 25295618 PMCID: PMC4189953 DOI: 10.1371/journal.pone.0108826] [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: 04/17/2014] [Accepted: 08/27/2014] [Indexed: 01/12/2023] Open
Abstract
To optimise the efficiency of cell machinery, cells can use the same protein (often called a hub protein) to participate in different cell functions by simply changing its target molecules. There are large data sets describing protein-protein interactions (“interactome”) but they frequently fail to consider the functional significance of the interactions themselves. We studied the interaction between two potential hub proteins, ICln and 4.1R (in the form of its two splicing variants 4.1R80 and 4.1R135), which are involved in such crucial cell functions as proliferation, RNA processing, cytoskeleton organisation and volume regulation. The sub-cellular localisation and role of native and chimeric 4.1R over-expressed proteins in human embryonic kidney (HEK) 293 cells were examined. ICln interacts with both 4.1R80 and 4.1R135 and its over-expression displaces 4.1R from the membrane regions, thus affecting 4.1R interaction with ß-actin. It was found that 4.1R80 and 4.1R135 are differently involved in regulating the swelling activated anion current (ICl,swell) upon hypotonic shock, a condition under which both isoforms are dislocated from the membrane region and thus contribute to ICl,swell current regulation. Both 4.1R isoforms are also differently involved in regulating cell morphology, and ICln counteracts their effects. The findings of this study confirm that 4.1R plays a role in cell volume regulation and cell morphology and indicate that ICln is a new negative regulator of 4.1R functions.
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Affiliation(s)
- Claudia Bazzini
- Department of Biosciences, University of Milan, Milan, Italy
| | - Lorena Benedetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
- Fondazione Filarete for Biosciences and Innovation, Milan, Italy
| | - Davide Civello
- Department of Biosciences, University of Milan, Milan, Italy
| | - Chiara Zanoni
- Pharmaceutical Sciences Department (DISFARM), University of Milan, Milan, Italy
| | | | - Davide Marchesi
- Fondazione Filarete for Biosciences and Innovation, Milan, Italy
| | | | - Markus Paulmichl
- Institute of Pharmacology and Toxicology, Paracelsus Medical University, Salzburg, Austria
| | - Maura Francolini
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
- Fondazione Filarete for Biosciences and Innovation, Milan, Italy
| | - Giuliano Meyer
- Department of Biosciences, University of Milan, Milan, Italy
| | - Simona Rodighiero
- Fondazione Filarete for Biosciences and Innovation, Milan, Italy
- * E-mail:
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Insights into the Function of the Unstructured N-Terminal Domain of Proteins 4.1R and 4.1G in Erythropoiesis. Int J Cell Biol 2011; 2011:943272. [PMID: 21904552 PMCID: PMC3166722 DOI: 10.1155/2011/943272] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 06/20/2011] [Indexed: 01/26/2023] Open
Abstract
Membrane skeletal protein 4.1R is the prototypical member of a family of four highly paralogous proteins that include 4.1G, 4.1N, and 4.1B. Two isoforms of 4.1R (4.1R(135) and 4.1R(80)), as well as 4.1G, are expressed in erythroblasts during terminal differentiation, but only 4.1R(80) is present in mature erythrocytes. One goal in the field is to better understand the complex regulation of cell type and isoform-specific expression of 4.1 proteins. To start answering these questions, we are studying in depth the important functions of 4.1 proteins in the organization and function of the membrane skeleton in erythrocytes. We have previously reported that the binding profiles of 4.1R(80) and 4.1R(135) to membrane proteins and calmodulin are very different despite the similar structure of the membrane-binding domain of 4.1G and 4.1R(135). We have accumulated evidence for those differences being caused by the N-terminal 209 amino acids headpiece region (HP). Interestingly, the HP region is an unstructured domain. Here we present an overview of the differences and similarities between 4.1 isoforms and paralogs. We also discuss the biological significance of unstructured domains.
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Alternative splicing regulates mouse embryonic stem cell pluripotency and differentiation. Proc Natl Acad Sci U S A 2010; 107:10514-9. [PMID: 20498046 DOI: 10.1073/pnas.0912260107] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Two major goals of regenerative medicine are to reproducibly transform adult somatic cells into a pluripotent state and to control their differentiation into specific cell fates. Progress toward these goals would be greatly helped by obtaining a complete picture of the RNA isoforms produced by these cells due to alternative splicing (AS) and alternative promoter selection (APS). To investigate the roles of AS and APS, reciprocal exon-exon junctions were interrogated on a genome-wide scale in differentiating mouse embryonic stem (ES) cells with a prototype Affymetrix microarray. Using a recently released open-source software package named AltAnalyze, we identified 144 genes for 170 putative isoform variants, the majority (67%) of which were predicted to alter protein sequence and domain composition. Verified alternative exons were largely associated with pathways of Wnt signaling and cell-cycle control, and most were conserved between mouse and human. To examine the functional impact of AS, we characterized isoforms for two genes. As predicted by AltAnalyze, we found that alternative isoforms of the gene Serca2 were targeted by distinct microRNAs (miRNA-200b, miRNA-214), suggesting a critical role for AS in cardiac development. Analysis of the Wnt transcription factor Tcf3, using selective knockdown of an ES cell-enriched and characterized isoform, revealed several distinct targets for transcriptional repression (Stmn2, Ccnd2, Atf3, Klf4, Nodal, and Jun) as well as distinct differentiation outcomes in ES cells. The findings herein illustrate a critical role for AS in the specification of ES cells with differentiation, and highlight the utility of global functional analyses of AS.
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Treviño MA, Rodríguez-Rodríguez M, Correas I, Marcilla M, Albar JP, Rico M, Jiménez MA, Bruix M. NMR characterisation of the minimal interacting regions of centrosomal proteins 4.1R and NuMA1: effect of phosphorylation. BMC BIOCHEMISTRY 2010; 11:7. [PMID: 20109190 PMCID: PMC2834593 DOI: 10.1186/1471-2091-11-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 01/28/2010] [Indexed: 11/17/2022]
Abstract
Background Some functions of 4.1R in non-erythroid cells are directly related with its distinct sub-cellular localisation during cell cycle phases. During mitosis, 4.1R is implicated in cell cycle progression and spindle pole formation, and co-localizes with NuMA1. However, during interphase 4.1R is located in the nucleus and only partially co-localizes with NuMA1. Results We have characterized by NMR the structural features of the C-terminal domain of 4.1R and those of the minimal region (the last 64 residues) involved in the interaction with NuMA1. This subdomain behaves as an intrinsically unfolded protein containing a central region with helical tendency. The specific residues implicated in the interaction with NuMA1 have been mapped by NMR titrations and involve the N-terminal and central helical regions. The segment of NuMA1 that interacts with 4.1R is phosphorylated during mitosis. Interestingly, NMR data indicates that the phosphorylation of NuMA1 interacting peptide provokes a change in the interaction mechanism. In this case, the recognition occurs through the central helical region as well as through the C-terminal region of the subdomain meanwhile the N-terminal region do not interact. Conclusions These changes in the interaction derived from the phosphorylation state of NuMA1 suggest that phosphorylation can act as subtle mechanism of temporal and spatial regulation of the complex 4.1R-NuMA1 and therefore of the processes where both proteins play a role.
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Affiliation(s)
- Miguel A Treviño
- Departamento de Espectroscopía y Estructura Molecular, Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain.
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Seo PS, Jeong JJ, Zeng L, Takoudis CG, Quinn BJ, Khan AA, Hanada T, Chishti AH. Alternatively spliced exon 5 of the FERM domain of protein 4.1R encodes a novel binding site for erythrocyte p55 and is critical for membrane targeting in epithelial cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:281-9. [PMID: 18952129 DOI: 10.1016/j.bbamcr.2008.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 09/12/2008] [Accepted: 09/17/2008] [Indexed: 01/18/2023]
Abstract
Direct physical linkage of MAGUKs to the actin cytoskeleton was first established by the interaction of erythrocyte p55 with the FERM domain of protein 4.1R. Subsequently, it was reported that p55 binds to a 51-amino acid peptide, encoded by exon 10, located within the FERM domain of protein 4.1R. In this study, we investigated the nature of the p55-FERM domain binding interface and show that p55 binds to a second 35-amino acid peptide, encoded by an alternatively spliced exon 5, located within the FERM domain of protein 4.1R. Competition and Surface Plasmon Resonance-binding measurements suggest that the peptides encoded by exons 5 and 10 bind to independent sites within the D5 domain of p55. Interestingly, the full length 135 kDa isoform of protein 4.1R containing both exons 5 and 10 was targeted exclusively to the plasma membrane of epithelial cells whereas the same isoform without exon 5 completely lost its membrane localization capacity. Together, these results indicate that p55 binds to two distinct sites within the FERM domain, and the alternatively spliced exon 5 is necessary for the membrane targeting of protein 4.1R in epithelial cells. Since sequences similar to the exon 5-peptide of protein 4.1R and D5 domain of p55 are conserved in many proteins, our findings suggest that a similar mechanism may govern the membrane targeting of other FERM domain containing proteins.
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Affiliation(s)
- Pil-Soo Seo
- Department of Pharmacology, UIC Cancer Center, University of Illinois College of Medicine, Chicago, IL 60612, USA
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Yang S, Liu X, Yin Y, Fukuda MN, Zhou J. Tastin is required for bipolar spindle assembly and centrosome integrity during mitosis. FASEB J 2008; 22:1960-72. [PMID: 18218922 DOI: 10.1096/fj.07-081463] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tastin was previously characterized as an accessory protein for cell adhesion that participates in early embryo implantation. Here, we report that tastin is also required for spindle assembly during mitosis. Tastin protein levels peaked in the G(2)/M phase and abruptly declined after cell division. Microscopy showed that tastin is primarily localized on the microtubules, centrosomes, and the mitotic spindle during the cell cycle. Tastin interacted with the dynein intermediate chain, p150(Glued), and gamma-tubulin in addition to Tctex-1 (the light chain of dynein). Overexpression of tastin led to monopolar spindle formation, whereas loss of tastin expression caused profound mitotic block and preferentially induced multipolar spindles. These multipolar spindles were generated through a loss of cohesion in mitotic centrosomes; specifically, tastin depletion caused the fragmentation of pericentrosomal material and the splitting of the centrioles at the spindle poles. Tastin depletion induced centrosome abnormalities exclusively during mitosis and required both microtubule integrity and Eg5 activity. However, tastin depletion did not disrupt the organization of spindle poles, as revealed by localization of nuclear mitotic apparatus protein (NuMA) and the p150(Glued) component of dynactin. These data indicate that the major function of tastin during mitosis is to maintain the structural and dynamic features of centrosomes, thereby contributing to spindle bipolarity.
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Affiliation(s)
- Shuo Yang
- Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
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Yang G, Huang SC, Wu JY, Benz EJ. Regulated Fox-2 isoform expression mediates protein 4.1R splicing during erythroid differentiation. Blood 2007; 111:392-401. [PMID: 17715393 PMCID: PMC2200819 DOI: 10.1182/blood-2007-01-068940] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A regulated splicing event in protein 4.1R pre-mRNA-the inclusion of exon 16-encoding peptides for spectrin-actin binding-occurs in late erythroid differentiation. We defined the functional significance of an intronic splicing enhancer, UGCAUG, and its cognate splicing factor, mFox2A, on exon 16 splicing during differentiation. UGCAUG displays cell-type-specific splicing regulation in a test neutral reporter and has a dose-dependent enhancing effect. Erythroid cells express 2 UGCAUG-binding mFox-2 isoforms, an erythroid differentiation-inducible mFox-2A and a commonly expressed mFox-2F. When overexpressed, both enhanced internal exon splicing in an UGCAUG-dependent manner, with mFox-2A exerting a much stronger effect than mFox-2F. A significant reciprocal increase in mFox-2A and decrease in mFox-2F occurred during erythroid differentiation and correlated with exon 16 inclusion. Furthermore, isoform-specific expression reduction reversed mFox-2A-enhancing activity, but not that of mFox-2F on exon 16 inclusion. Our results suggest that an erythroid differentiation-inducible mFox-2A isoform is a critical regulator of the differentiation-specific exon 16 splicing switch, and that its up-regulation in late erythroid differentiation is vital for exon 16 splicing.
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Affiliation(s)
- Guang Yang
- Department of Medical Oncology, Dana-Farber Cancer Institute, 44 Binney St, Boston, MA 02115, USA
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Tang BL. Molecular genetic determinants of human brain size. Biochem Biophys Res Commun 2006; 345:911-6. [PMID: 16716254 DOI: 10.1016/j.bbrc.2006.05.040] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 05/08/2006] [Indexed: 12/17/2022]
Abstract
Cognitive skills such as tool use, syntactical languages, and self-awareness differentiate humans from other primates. The underlying basis for this cognitive difference has been widely associated with a high encephalization quotient and an anatomically distinct, exceptionally large cerebral cortex. Investigations on congenital microcephaly had revealed several genes that affect mammalian brain size when mutated. At least four of these, microcephalin (MCPH1), abnormal spindle-like microcephaly-associated (ASPM), cyclin-dependent kinase 5 regulatory associated protein 2 (CDK5RAP2), and centromere-associated protein J (CENPJ) are known to have undergone significant positive selection in the great apes and human lineages during primate evolution. MCPH1 and ASPM both have very young single nucleotide polymorphism haplotypes associated with modern humans, and these genes are presumably still evolving in Homo sapiens. Microcephalin has a role in DNA damage response and regulation of cell cycle checkpoints. The other known microcephaly-associated genes encode microtubule-associated centrosomal proteins that might regulate neural progenitor cell division and cell number. Recent reports have also unveiled a previously unknown function of ephrins and Eph in the regulation of neural progenitor cell death with a consequential effect on brain size. Understanding the mechanism for developmental control of brain organogenesis by these genes, and others such as FOXP2, shall provide fresh perspectives on the evolution of human intelligence.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore.
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Bond J, Woods CG. Cytoskeletal genes regulating brain size. Curr Opin Cell Biol 2006; 18:95-101. [PMID: 16337370 DOI: 10.1016/j.ceb.2005.11.004] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 11/24/2005] [Indexed: 11/22/2022]
Abstract
One of the most notable trends in human evolution is the dramatic increase in brain size that has occurred in the great ape clade, culminating in humans. Of particular interest is the vast expanse of the cerebral cortex, which is believed to have resulted in our ability to perform higher cognitive functions. Recent investigations of congenital microcephaly in humans have resulted in the identification of several genes that non-redundantly and specifically influence mammalian brain size. These genes appear to affect neural progenitor cell number through microtubular organisation at the centrosome.
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Affiliation(s)
- Jacquelyn Bond
- Molecular Medicine Unit, University of Leeds, Clinical Sciences Building, St James's University Hospital, Beckett St., Leeds, West Yorkshire, LS9 7TF, UK.
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