Int J Biochem Cell Biol
Institute of Genetics and Cytology, Northeast Normal University, Changchun, China; Department of Bioscience, Shanxi University, Taiyuan, China.
Published: December 2013
P-selectin glycoprotein ligand-1 and β1 integrin play essential roles in T cell trafficking during inflammation. E-selectin and vascular cell adhesion molecule-1 are their ligands expressed on inflammation-activated endothelium. During the tethering and rolling of lymphocytes on endothelium, P-selectin glycoprotein ligand-1 binds E-selectin and induces signals. Subsequently, β1 integrin is activated and mediates stable adhesion. However, the intracellular signal pathways from PSGL-1 to β1 integrin have not yet been fully understood. Here, we find that p85, a regulatory subunit of phosphoinositide 3-kinase, forms a novel complex with Rho-GDP dissociation inhibitor-2, a lymphocyte-specific RhoGTPases dissociation inhibitor. Phosporylations of the p85-bound Rho-GDP dissociation inhibitor-2 on 130 and 153 tyrosine residues by c-Abl and Src were required for the complex to be recruited to P-selectin glycoprotein ligand-1 and thereby regulate β1 integrin-mediated T cell adhesion to vascular cell adhesion molecule-1. Both shRNAs to Rho-GDP dissociation inhibitor-2 and p85 and over-expression of Rho-GDP dissociation inhibitor-2 Y130F and Y153F significantly reduced the above-mentioned adhesion. Although Rho-GDP dissociation inhibitor-2 in the p85-Rho-GDP dissociation inhibitor-2 complex was also phosphorylated on 24 tyrosine residue by Syk, the phosphorylation is not required for the adhesion. Taken together, we find that specific phosphorylations on 130 and 153 tyrosine residues of p85-bound Rho-GDP dissociation inhibitor-2 are pivotal for P-selectin glycoprotein ligand-1-induced β1 integrin-mediated lymphocyte adhesion to vascular cell adhesion molecule-1. This will shed new light on the mechanisms that connect leukocyte initial rolling with subsequent adhesion.
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http://dx.doi.org/10.1016/j.biocel.2013.09.005 | DOI Listing |
Sci Adv
December 2024
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
HER2 and αβ integrin are independent predictors of breast cancer survival and metastasis. We identify an αβ/HER2 cross-talk mechanism driving invasion, which is dysregulated in drug-resistant HER2+ breast cancer cells. Proteomic analyses reveal ligand-bound αβ recruits HER2 and a trafficking subnetwork, comprising guanosine triphosphatases RAB5 and RAB7A and the Rab regulator guanine nucleotide dissociation inhibitor 2 (GDI2).
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September 2024
Affiliated Hospital of Guangdong Medical University, No. 57, South of Renmin Avenue, Zhanjiang, 524001, China.
Objective: To investigate the effect of silencing GDP dissociation inhibitor 2 (GDI2) on colorectal cancer development and possible mechanisms based on transcriptomic analysis.
Methods: The differences in the expression levels of GDI2 in normal colorectal tissues and tumor tissues of colorectal cancer (CRC) patients were detected. The correlation of GDI2 expression levels with survival and clinical characteristics of CRC patients was analyzed.
J Cancer
May 2024
Department of Cell Biology, School of Medicine, Nankai University, Tianjin, 300071, China.
: Liver hepatocellular carcinoma (LIHC) is one of the leading causes of cancer-related death. The prognostic outcomes of advanced LIHC patients are poor. Hence, reliable prognostic biomarkers for LIHC are urgently needed.
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February 2024
Research Service, John D. Dingell VA Medical Center, Detroit, MI 48201, USA.
Small G proteins (e.g., Rac1) play critical regulatory roles in islet β-cell function in health (physiological insulin secretion) and in metabolic stress (cell dysfunction and demise).
View Article and Find Full Text PDFHLA
February 2023
Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
Antibodies against Rho GDP-dissociation inhibitor 2 (RhoGDI2) are associated with inferior graft survival in transplant patients receiving a kidney from deceased donors. Although this suggests that these antibodies contribute to graft injury because of ischemia, it remains unknown whether they are also pathogenically involved in the process of graft loss. To study this, we firstly analyzed the IgG subclass profile of anti-RhoGDI2 antibodies in kidney transplant recipients, and whether antibody titers change over time or because of acute rejection.
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