Tyrosine kinase activity of the asymmetric EGFR homodimer is negatively regulated via ERK-mediated phosphorylation of Thr-669 in the juxtamembrane domain. In the present study, we investigated in human breast cancer cells whether a similar mechanism plays a role in the feedback regulation of the ErbB2/ErbB3 heterodimer, the most potent ErbB receptor dimer. Constitutive tyrosine phosphorylation of ErbB2 and ErbB3 was significantly decreased in phorbol ester- and growth factor-treated BT-474 and MDA-MB-453 cells. In contrast to the decreased tyrosine phosphorylation, Phos-tag Western blot analysis revealed that TPA induced phosphorylation of ErbB2 in an ERK-dependent manner. The target threonine residue corresponding to EGFR Thr-669 and the surrounding residues are highly conserved in ErbB2, but not in ErbB3. Therefore, we demonstrated ERK-mediated phosphorylation of ErbB2 at Thr-677 by generating phospho-specific monoclonal antibodies. Moreover, treatment with trametinib and SCH772984, inhibitors of the MEK-ERK pathway, and substitution of Thr-677 to alanine impaired the feedback inhibition of ErbB2 and ErbB3. These results demonstrated that ERK-mediated phosphorylation of the conserved threonine is a common mechanism for the negative feedback control of active ErbB receptor dimers.
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http://dx.doi.org/10.1038/srep31502 | DOI Listing |
Transl Stroke Res
December 2024
Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Rd, Yuzhong, Chongqing, 400010, China.
Perihematomal edema (PHE) significantly aggravates secondary brain injury in patients with intracerebral hemorrhage (ICH), yet its detailed mechanisms remain elusive. Neutrophil extracellular traps (NETs) are known to exacerbate neurological deficits and worsen outcomes after stroke. This study explores the potential role of NETs in the pathogenesis of brain edema following ICH.
View Article and Find Full Text PDFMetabolism
February 2025
Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation & Molecular Target and Clinical Pharmacology, the State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences & the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong 511436, China. Electronic address:
PPARγ functions as a master ligand-dependent transcription factor that regulates the expressions of a variety of key genes related to metabolic homeostasis and inflammatory immunity. It has been recognized as a popular and druggable target in modern drug discovery. Similar to other nuclear receptors, PPARγ is a phosphoprotein, and its biological functions are regulated by phosphorylation, especially at Ser273 site which is mediated by CDK5 or ERK.
View Article and Find Full Text PDFCell Metab
November 2024
Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China. Electronic address:
Lactyl-coenzyme A (CoA)-dependent histone lysine lactylation impacts gene expression and plays fundamental roles in biological processes. However, mammalian lactyl-CoA synthetases and their regulation of histone lactylation have not yet been identified. Here, we demonstrate that epidermal growth factor receptor (EGFR) activation induces extracellular signal-regulated kinase (ERK)-mediated S267 phosphorylation of acetyl-CoA synthetase 2 (ACSS2) and its subsequent nuclear translocation and complex formation with lysine acetyltransferase 2A (KAT2A).
View Article and Find Full Text PDFMetabolism
January 2025
Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark. Electronic address:
Background: Protein kinase CK2 is a highly conserved enzyme implicated in the pathogenesis of various human illnesses including obesity. Despite compelling evidence for the involvement of this kinase in the pathophysiology of obesity, the molecular mechanisms by which CK2 might regulate fat metabolism are still poorly understood.
Methods And Results: In this study, we aimed to elucidate the role of CK2 on lipid metabolism by employing both in vitro and in vivo approaches using mouse pre-adipocytes and a mouse model of diet-induced obesity.
Phytomedicine
December 2024
Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkiye.
Background: Glioblastoma (GB) is a highly malignant type of brain cancer with a poor prognosis. Therapeutic strategies for GB are still limited. Rosmarinic acid (RA), a polyphenolic compound, is a promising experimental anticancer agent, but its specific protein targets for GB remain unclear.
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