The transmembrane receptor CD44 conveys important signals from the extracellular microenvironment to the cytoplasm, a phenomena known as "outside-in" signaling. CD44 exists as several isoforms that result from alternative splicing, which differ only in the extracellular domain but yet exhibit different activities. CD44 is a binding partner for the membrane-cytoskeleton cross-linker protein ezrin. In this study, we demonstrate that only CD44 standard (CD44s) colocalizes and interacts with the actin cross-linkers ezrin and moesin using well-characterized cell lines engineered to express different CD44 isoforms. Importantly, we also show that the association CD44s-ezrin-actin is an important modulator of Fas-mediated apoptosis. The results highlight a mechanism by which signals from the extracellular milieu regulate intracellular signaling activities involved in programmed cell death.
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http://dx.doi.org/10.1007/s10495-007-0115-3 | DOI Listing |
J Biol Chem
January 2025
Institute of Biochemistry and Molecular Biology II, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany. Electronic address:
Recently, we phenocopied Interleukin (IL-)6 signaling using the dimerized single-chain variable fragment (scFv) derived from the respiratory syncytial virus (RSV) IgG1-antibody Palivizumab (PLHFc) to activate a Palivizumab anti-idiotypic nanobody (AIP)-gp130 receptor fusion protein. Palivizumab was unable to activate STAT3 signaling, so we aimed to create a similar ligand capable of triggering this pathway. Here, we created three variants of the ligand called PLH0Fc, PLH4Fc and PLH8Fc by shortening the spacer region connecting PLH and Fc from 23 amino acids in PLHFc to 0 amino acids or expanding it by rigid linkers of 4 or 8 alpha helical loops, respectively.
View Article and Find Full Text PDFJ Biol Chem
November 2024
Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA. Electronic address:
The TNF-TNFR1 signaling pathway plays a pivotal role in regulating the balance between cell survival and cell death. Upon binding to TNF, plasma membrane-localized TNFR1 initiates survival signaling, whereas TNFR1 internalization promotes caspase-mediated apoptosis. We previously reported that the α2-6 sialylation of TNFR1 by the tumor-associated sialyltransferase ST6GAL1 diverts signaling toward survival by inhibiting TNFR1 internalization.
View Article and Find Full Text PDFiScience
November 2024
Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, China.
Biomolecules
September 2024
Metabolic Control and Aging-Jiangxi Key Laboratory of Aging and Diseases, Human Aging Research Institute (HARI), School of Life Science, Nanchang University, Nanchang 330031, China.
The regenerative capacity of muscle, which primarily relies on anabolic processes, diminishes with age, thereby reducing the effectiveness of therapeutic interventions aimed at treating age-related muscle atrophy. In this study, we observed a decline in the expression of methionine adenosine transferase 2A (MAT2A), which synthesizes S-adenosylmethionine (SAM), in the muscle tissues of both aged humans and mice. Considering MAT2A's critical role in anabolism, we hypothesized that its reduced expression contributes to the impaired regenerative capacity of aging skeletal muscle.
View Article and Find Full Text PDFNeurol Int
August 2024
Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA.
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