1
|
Kimmich MJ, Sundaramurthy S, Geary MA, Lesanpezeshki L, Yingling CV, Vanapalli SA, Littlefield RS, Pruyne D. FHOD-1/profilin-mediated actin assembly protects sarcomeres against contraction-induced deformation in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582848. [PMID: 38559004 PMCID: PMC10979920 DOI: 10.1101/2024.02.29.582848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Formin HOmology Domain 2-containing (FHOD) proteins are a subfamily of actin-organizing formins important for striated muscle development in many animals. We showed previously that absence of the sole FHOD protein, FHOD-1, from C. elegans results in thin body-wall muscles with misshapen dense bodies that serve as sarcomere Z-lines. We demonstrate here that actin polymerization by FHOD-1 is required for its function in muscle development, and that FHOD-1 cooperates with profilin PFN-3 for dense body morphogenesis, and profilins PFN-2 and PFN-3 to promote body-wall muscle growth. We further demonstrate dense bodies in fhod-1 and pfn-3 mutants are less stable than in wild type animals, having a higher proportion of dynamic protein, and becoming distorted by prolonged muscle contraction. We also observe accumulation of actin depolymerization factor/cofilin homolog UNC-60B in body-wall muscle of these mutants. Such accumulations may indicate targeted disassembly of thin filaments dislodged from unstable dense bodies, and may account for the abnormally slow growth and reduced strength of body-wall muscle in fhod-1 mutants. Overall, these results show the importance of FHOD protein-mediated actin assembly to forming stable sarcomere Z-lines, and identify profilin as a new contributor to FHOD activity in striated muscle development.
Collapse
Affiliation(s)
- Michael J. Kimmich
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Sumana Sundaramurthy
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Meaghan A. Geary
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Leila Lesanpezeshki
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409
| | - Curtis V. Yingling
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| | - Siva A. Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409
| | | | - David Pruyne
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210
| |
Collapse
|
2
|
Yan M, Tang L, Dai L, Lei C, Xiong M, Zhang X, He M, Tian Y, Xiong J, Ke W, Zhang Z, Zhang C, Deng X, Zhang Z. Cofilin promotes tau pathology in Alzheimer's disease. Cell Rep 2023; 42:112138. [PMID: 36807141 DOI: 10.1016/j.celrep.2023.112138] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 12/20/2022] [Accepted: 02/02/2023] [Indexed: 02/19/2023] Open
Abstract
The molecular mechanisms mediating the aggregation and transmission of tau in AD remain unclear. Here, we show that the actin-binding protein cofilin is cleaved by a cysteine protease asparagine endopeptidase (AEP) at N138 in the brains of patients with AD. The AEP-generated cofilin 1-138 fragment interacts with tau and promotes its aggregation. The mixed fibrils consisting of cofilin 1-138 and tau are more pathogenic to cells than pure tau fibrils. Furthermore, overexpression of cofilin 1-138 in the brain facilitates the propagation of pathological tau aggregates and promotes AD-like cognitive impairments in tau P301S mice. However, mice infected with adeno-associated viruses (AAVs) encoding an AEP-uncleavable cofilin mutant show attenuated tau pathology and cognitive impairments compared with mice injected with AAVs encoding wild-type cofilin. Together, these observations support the role of the cofilin 1-138 fragment in the aggregation and transmission of tau pathology during the onset and progression of AD.
Collapse
Affiliation(s)
- Mingmin Yan
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Department of Neurology, Hubei No. 3 People's Hospital of Jianghan University, Wuhan 430060, China
| | - Li Tang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Lijun Dai
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Chuntao Lei
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430060, China
| | - Min Xiong
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Xingyu Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Mingyang He
- Hubei Provincial Institute for Food Supervision and Test, Wuhan 430060, China
| | - Ye Tian
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Jing Xiong
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Wei Ke
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430060, China
| | - Xiaorong Deng
- Department of Neurology, Hubei No. 3 People's Hospital of Jianghan University, Wuhan 430060, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
| |
Collapse
|
3
|
Takayama K, Matsuda K, Abe H. Formation of actin-cofilin rods by depletion forces. Biochem Biophys Res Commun 2022; 626:200-204. [PMID: 35994830 DOI: 10.1016/j.bbrc.2022.08.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 07/28/2022] [Accepted: 08/08/2022] [Indexed: 11/02/2022]
Abstract
Various stress conditions induce the formation of actin-cofilin rods in either the nucleus or the cytoplasm, although the mechanism of rod formation is unclear. In this study, we constituted actin-cofilin rods using purified actin, cofilin and actin interacting protein 1 (AIP1) in the presence of a physiological buffer containing a crowding agent, 0.8% methylcellulose (MC), which led to bundled actin filaments formed by depletion forces. Most of the F-actin bundles formed with methylcellulose were linear, whereas cofilin-bound F-actin bundles often had bent, looped, and often ring-like shapes. Increasing the amount of AIP1 shortened actin-cofilin bundles into rod-like bundles with tapering at both ends. As much shorter actin-cofilin filaments were formed in the presence of AIP1 before MC was added to the mixture, the rod-like bundle might be a mass of those short filaments. Furthermore, the small rods fused with each other to become larger rods, indicating that these rods were anisotropic liquid droplets. Several minutes after the addition of MC to the F-actin-cofilin-AIP1 mixture, we observed some long bundles in which the thick and thin parts appear alternately, reminiscent of a Plateau-Rayleigh instability observed in fluid columns. Simultaneously, we found images in which thin parts were interrupted, but the thick parts were arranged in a row in the longitudinal direction. These structures were also observed in cytoplasmic actin-cofilin rods in cells overexpressing cofilin-GFP, suggesting that cytoplasmic actin-cofilin rods have the same structure formation process as the rods reconstituted in vitro.
Collapse
Affiliation(s)
- Kohki Takayama
- Department of Biology, Graduate School of Science and Engineering, Chiba University, Chiba, 263-8522, Japan
| | - Kota Matsuda
- Department of Biology, Graduate School of Science and Engineering, Chiba University, Chiba, 263-8522, Japan
| | - Hiroshi Abe
- Department of Biology, Graduate School of Science and Engineering, Chiba University, Chiba, 263-8522, Japan; Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan.
| |
Collapse
|
4
|
Raiders SA, Eastwood MD, Bacher M, Priess JR. Binucleate germ cells in Caenorhabditis elegans are removed by physiological apoptosis. PLoS Genet 2018; 14:e1007417. [PMID: 30024879 PMCID: PMC6053125 DOI: 10.1371/journal.pgen.1007417] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022] Open
Abstract
Cell death plays a major role during C. elegans oogenesis, where over half of the oogenic germ cells die in a process termed physiological apoptosis. How germ cells are selected for physiological apoptosis, or instead become oocytes, is not understood. Most oocytes produce viable embryos when apoptosis is blocked, suggesting that physiological apoptosis does not function to cull defective germ cells. Instead, cells targeted for apoptosis may function as nurse cells; the germline is syncytial, and all germ cells appear to contribute cytoplasm to developing oocytes. C. elegans has been a leading model for the genetics and molecular biology of apoptosis and phagocytosis, but comparatively few studies have examined the cell biology of apoptotic cells. We used live imaging to identify and examine pre-apoptotic germ cells in the adult gonad. After initiating apoptosis, germ cells selectively export their mitochondria into the shared pool of syncytial cytoplasm; this transport appears to use the microtubule motor kinesin. The apoptotic cells then shrink as they expel most of their remaining cytoplasm, and close off from the syncytium. Shortly thereafter the apoptotic cells restructure their microtubule and actin cytoskeletons, possibly to maintain cell integrity; the microtubules form a novel, cortical array of stabilized microtubules, and actin and cofilin organize into giant cofilin-actin rods. We discovered that some apoptotic germ cells are binucleate; the binucleate germ cells can develop into binucleate oocytes in apoptosis-defective strains, and appear capable of producing triploid offspring. Our results suggest that the nuclear layer of the germline syncytium becomes folded during mitosis and growth, and that binucleate cells arise as the layer unfolds or everts; all of the binucleate cells are subsequently removed by apoptosis. These results show that physiological apoptosis targets at least two distinct populations of germ cells, and that the apoptosis machinery efficiently recognizes cells with two nuclei. Many germ cells die by apoptosis during the development of animal oocytes, including more than half of all germ cells in the model system C. elegans. How individual germ cells are selected for apoptosis, or survival, is not known. Here we study the cell biology of apoptosis. The C. elegans gonad is a syncytium, with nearly 1000 germ “cells” connected to a shared, core cytoplasm. Once apoptosis is initiated, germ cells selectively transport their mitochondria into the gonad core, apparently using the microtubule motor protein kinesin. The apoptotic cells next constrict, expelling most of their remaining cytoplasm into the core, and close off from the gonad core. The microtubule and actin cytoskeletons are remodeled and stabilized, presumably to maintain the integrity of the dying cell. The apoptotic cells form giant cofilin-actin rods, similar to rods described in stressed cultured cells and in human myopathies and neuropathies such as Alzheimer’s and Huntington’s disease. We show that some germ cells are binucleate; these cells appear to form during germline morphogenesis, and are removed by apoptosis. These results demonstrate heterogeneity between oogenic germ cells, and show that the apoptosis machinery efficiently recognizes and removes cells with two nuclei.
Collapse
Affiliation(s)
- Stephan A. Raiders
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Michael D. Eastwood
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Meghan Bacher
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - James R. Priess
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
5
|
Functions of actin-interacting protein 1 (AIP1)/WD repeat protein 1 (WDR1) in actin filament dynamics and cytoskeletal regulation. Biochem Biophys Res Commun 2017; 506:315-322. [PMID: 29056508 DOI: 10.1016/j.bbrc.2017.10.096] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 10/18/2017] [Indexed: 02/04/2023]
Abstract
Actin-depolymerizing factor (ADF)/cofilin and actin-interacting protein 1 (AIP1), also known as WD-repeat protein 1 (WDR1), are conserved among eukaryotes and play critical roles in dynamic reorganization of the actin cytoskeleton. AIP1 preferentially promotes disassembly of ADF/cofilin-decorated actin filaments but exhibits minimal effects on bare actin filaments. Therefore, AIP1 has been often considered to be an ancillary co-factor of ADF/cofilin that merely boosts ADF/cofilin activity level. However, genetic and cell biological studies show that AIP1 deficiency often causes lethality or severe abnormalities in multiple tissues and organs including muscle, epithelia, and blood, suggesting that AIP1 is a major regulator of many biological processes that depend on actin dynamics. This review summarizes recent progress in studies on the biochemical mechanism of actin filament severing by AIP1 and in vivo functions of AIP1 in model organisms and human diseases.
Collapse
|
6
|
Obinata T, Ono K, Ono S. Detection of a troponin I-like protein in non-striated muscle of the tardigrades (water bears). BIOARCHITECTURE 2011; 1:96-102. [PMID: 21866271 DOI: 10.4161/bioa.1.2.16251] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 04/29/2011] [Indexed: 12/29/2022]
Abstract
Tardigrades, also known as water bears, have somatic muscle fibers that are responsible for movement of their body and legs. These muscle fibers contain thin and thick filaments in a non-striated pattern. However, the regulatory mechanism of muscle contraction in tardigrades is unknown. In the absence of extensive molecular and genomic information, we detected a protein of 31 kDa in whole lysates of tardigrades that cross-reacted with the antibody raised against nematode troponin I (TnI). TnI is a component of the troponin complex that regulates actin-myosin interaction in a Ca(2+)-dependent and actin-linked manner. This TnI-like protein was co-extracted with actin in a buffer containing ATP and EGTA, which is known to induce relaxation of a troponin-regulated contractile system. The TnI-like protein was specifically expressed in the somatic muscle fibers in adult animals and partially co-localized with actin filaments in a non-striated manner. Interestingly, the pharyngeal muscle did not express this protein. These observations suggest that the non-striated somatic muscle of tardigrades has an actin-linked and troponin-regulated system for muscle contraction.
Collapse
Affiliation(s)
- Takashi Obinata
- Department of Biology; Faculty of Science; Chiba University; Chiba, Japan
| | | | | |
Collapse
|
7
|
Ono S. Dynamic regulation of sarcomeric actin filaments in striated muscle. Cytoskeleton (Hoboken) 2010; 67:677-92. [PMID: 20737540 PMCID: PMC2963174 DOI: 10.1002/cm.20476] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 07/21/2010] [Accepted: 07/29/2010] [Indexed: 01/08/2023]
Abstract
In striated muscle, the actin cytoskeleton is differentiated into myofibrils. Actin and myosin filaments are organized in sarcomeres and specialized for producing contractile forces. Regular arrangement of actin filaments with uniform length and polarity is critical for the contractile function. However, the mechanisms of assembly and maintenance of sarcomeric actin filaments in striated muscle are not completely understood. Live imaging of actin in striated muscle has revealed that actin subunits within sarcomeric actin filaments are dynamically exchanged without altering overall sarcomeric structures. A number of regulators for actin dynamics have been identified, and malfunction of these regulators often result in disorganization of myofibril structures or muscle diseases. Therefore, proper regulation of actin dynamics in striated muscle is critical for assembly and maintenance of functional myofibrils. Recent studies have suggested that both enhancers of actin dynamics and stabilizers of actin filaments are important for sarcomeric actin organization. Further investigation of the regulatory mechanism of actin dynamics in striated muscle should be a key to understanding how myofibrils develop and operate.
Collapse
Affiliation(s)
- Shoichiro Ono
- Department of Pathology and Department of Cell Biology, Emory University, Atlanta, Georgia 30322, USA.
| |
Collapse
|
8
|
Obinata T, Ono K, Ono S. Troponin I controls ovulatory contraction of non-striated actomyosin networks in the C. elegans somatic gonad. J Cell Sci 2010; 123:1557-66. [PMID: 20388732 DOI: 10.1242/jcs.065060] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The myoepithelial sheath of the Caenorhabditis elegans somatic gonad has non-striated actomyosin networks that provide contractile forces during ovulation, a process in which a mature oocyte is expelled from the ovary. Troponin T and troponin C are known regulators of contraction of the myoepithelial sheath. These are two of the three components of the troponin complex that is generally considered as a striated-muscle-specific regulator of actomyosin contraction. Here, we report identification of troponin I as the third component of the troponin complex that regulates ovulatory contraction of the myoepithelial sheath. C. elegans has four genes encoding troponin-I isoforms. We found that tni-1 and unc-27 (also known as tni-2) encode two major troponin-I isoforms in the myoepithelial sheath. Combination of RNA interference and mutation of tni-1 and unc-27 resulted in loss of the troponin-I protein in the gonad and caused sterility due to defective contraction of the myoepithelial sheath. Troponin-I-depleted gonads were hypercontracted, which is consistent with the function of troponin I as an inhibitor of actomyosin contraction. Troponin I was associated with non-striated actin networks in a tropomyosin-dependent manner. Our results demonstrate that troponin I regulates contraction of non-striated actomyosin networks and is an essential cytoskeletal component of the C. elegans reproductive system.
Collapse
Affiliation(s)
- Takashi Obinata
- Department of Health and Nutrition, Teikyo-Heisei University, Tokyo 170-8445, Japan
| | | | | |
Collapse
|