1
|
Coulombe PA, Pineda CM, Jacob JT, Nair RR. Nuclear roles for non-lamin intermediate filament proteins. Curr Opin Cell Biol 2024; 86:102303. [PMID: 38113712 PMCID: PMC11056187 DOI: 10.1016/j.ceb.2023.102303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/21/2023] [Accepted: 11/26/2023] [Indexed: 12/21/2023]
Abstract
The nuclear-localized lamins have long been thought to be the only intermediate filaments (IFs) with an impact on the architecture, properties, and functions of the nucleus. Recent studies, however, uncovered significant roles for IFs other than lamins (here referred to as "non-lamin IFs") in regulating key properties of the nucleus in various cell types and biological settings. In the cytoplasm, IFs often occur in the perinuclear space where they contribute to local stiffness and impact the shape and/or the integrity of the nucleus, particularly in cells under stress. In addition, selective non-lamin IF proteins can occur inside the nucleus where they partake in fundamental processes including nuclear architecture and chromatin organization, regulation of gene expression, cell cycle progression, and the repair of DNA damage. This text reviews the evidence supporting a role for non-lamin IF proteins in regulating various properties of the nucleus and highlights opportunities for further study.
Collapse
Affiliation(s)
- Pierre A Coulombe
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Dermatology, University of Michigan, Ann Arbor, MI 48109, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Christopher M Pineda
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Justin T Jacob
- Public Health Laboratory Division, District of Columbia Department of Forensic Sciences, Washington, DC 20024, USA
| | - Raji R Nair
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| |
Collapse
|
2
|
Abstract
High levels of the intermediate filament protein keratin 17 (K17) are associated with poor prognoses for several human carcinomas. Studies in mouse models have shown that K17 expression is positively associated with growth, survival, and inflammation in skin and that lack of K17 delays onset of tumorigenesis. K17 occurs in the nucleus of human and mouse tumor keratinocytes where it impacts chromatin architecture, gene expression, and cell proliferation. We report here that K17 is induced following DNA damage and promotes keratinocyte survival. The presence of nuclear K17 is required at an early stage of the double-stranded break (DSB) arm of the DNA damage and repair (DDR) cascade, consistent with its ability to associate with key DDR effectors, including γ-H2A.X, 53BP1, and DNA-PKcs. Mice lacking K17 or with attenuated K17 nuclear import showed curtailed initiation in a two-step skin carcinogenesis paradigm. The impact of nuclear-localized K17 on DDR and cell survival provides a basis for the link between K17 induction and poor clinical outcomes for several human carcinomas.
Collapse
MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene/administration & dosage
- 9,10-Dimethyl-1,2-benzanthracene/toxicity
- Active Transport, Cell Nucleus
- Animals
- Carcinogenesis/chemically induced
- Carcinogenesis/genetics
- Carcinogenesis/pathology
- Carcinoma/chemically induced
- Carcinoma/genetics
- Carcinoma/pathology
- Cell Nucleus/metabolism
- Cell Survival/genetics
- DNA Breaks, Double-Stranded/drug effects
- DNA Repair
- Female
- Gene Knockout Techniques
- HeLa Cells
- Humans
- Intravital Microscopy
- Keratin-17/genetics
- Keratin-17/metabolism
- Keratinocytes
- Keratins/genetics
- Keratins/metabolism
- Male
- Mice, Knockout
- Neoplasms, Experimental/chemically induced
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/pathology
- Time-Lapse Imaging
- Mice
Collapse
Affiliation(s)
- Raji R Nair
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Joshua Hsu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205
| | - Justin T Jacob
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205
| | - Christopher M Pineda
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Ryan P Hobbs
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205;
| | - Pierre A Coulombe
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109;
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205
- Department of Dermatology, University of Michigan, Ann Arbor, MI 48109
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109
| |
Collapse
|
3
|
Jacob JT, Nair RR, Poll BG, Pineda CM, Hobbs RP, Matunis MJ, Coulombe PA. Keratin 17 regulates nuclear morphology and chromatin organization. J Cell Sci 2020; 133:jcs254094. [PMID: 33008845 PMCID: PMC7648610 DOI: 10.1242/jcs.254094] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
Keratin 17 (KRT17; K17), a non-lamin intermediate filament protein, was recently found to occur in the nucleus. We report here on K17-dependent differences in nuclear morphology, chromatin organization, and cell proliferation. Human tumor keratinocyte cell lines lacking K17 exhibit flatter nuclei relative to normal. Re-expression of wild-type K17, but not a mutant form lacking an intact nuclear localization signal (NLS), rescues nuclear morphology in KRT17-null cells. Analyses of primary cultures of skin keratinocytes from a mouse strain expressing K17 with a mutated NLS corroborated these findings. Proteomics screens identified K17-interacting nuclear proteins with known roles in gene expression, chromatin organization and RNA processing. Key histone modifications and LAP2β (an isoform encoded by TMPO) localization within the nucleus are altered in the absence of K17, correlating with decreased cell proliferation and suppression of GLI1 target genes. Nuclear K17 thus impacts nuclear morphology with an associated impact on chromatin organization, gene expression, and proliferation in epithelial cells.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Justin T Jacob
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Raji R Nair
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Brian G Poll
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Christopher M Pineda
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ryan P Hobbs
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Michael J Matunis
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Cell Biology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Pierre A Coulombe
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA
| |
Collapse
|