We have identified the Drosophila transmembrane molecule kekkon 1 (kek1) as an inhibitor of the epidermal growth factor receptor (EGFR) and demonstrate that it acts in a negative feedback loop to modulate the activity of the EGFR tyrosine kinase. During oogenesis, kek1 is expressed in response to the Gurken/EGFR signaling pathway, and loss of kek1 activity is associated with an increase in EGFR signaling. Consistent with our loss-of-function studies, we demonstrate that ectopic overexpression of kek1 mimics a loss of EGFR activity. We show that the extracellular and transmembrane domains of Kek1 can inhibit and physically associate with the EGFR, suggesting potential models for this inhibitory mechanism.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0092-8674(00)80594-2DOI Listing

Publication Analysis

Top Keywords

transmembrane molecule
8
molecule kekkon
8
feedback loop
8
kek1
5
egfr
5
kekkon acts
4
acts feedback
4
loop negatively
4
negatively regulate
4
activity
4

Similar Publications

Second harmonic generation (SHG) measurements using SHG-active dye molecules have recently attracted attention as a method to detect the formation of pores in phospholipid bilayers. The bilayers, in which the dye molecules are embedded in the outer leaflet, exhibit a noncentrosymmetric structure, generating SHG signals. However, when pores form, these dye molecules translocate through the pores into the inner leaflet, leading to a more centrosymmetric structure and the subsequent loss of the SHG signals.

View Article and Find Full Text PDF

Insight into the Mechanism of d-Glucose Accelerated Exchange in GLUT1 from Molecular Dynamics Simulations.

Biochemistry

January 2025

BHF Centre of Research Excellence, School of Medicine and Life Sciences, King's College London, London SE1 9NH, United Kingdom.

Transmembrane glucose transport, facilitated by glucose transporters (GLUTs), is commonly understood through the simple mobile carrier model (SMCM), which suggests that the central binding site alternates exposure between the inside and outside of the cell, facilitating glucose exchange. An alternative "multisite model" posits that glucose transport is a stochastic diffusion process between ligand-operated gates within the transporter's central channel. This study aims to test these models by conducting atomistic molecular dynamics simulations of multiple glucose molecules docked along the central cleft of GLUT1 at temperatures both above and below the lipid bilayer melting point.

View Article and Find Full Text PDF

functional validation of anti-CD19 chimeric antigen receptor T cells expressing lysine-specific demethylase 1 short hairpin RNA for the treatment of diffuse large B cell lymphoma.

Front Immunol

January 2025

Institute of Infection, Immunology and Tumor Microenvironment, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Medicine, Wuhan University of Science and Technology, Wuhan, China.

Background: Chimeric antigen receptor T (CAR-T) cell therapy is more effective in relapsed or refractory diffuse large B cell lymphoma (DLBCL) than other therapies, but a high proportion of patients relapse after CAR-T cell therapy owing to antigen escape, limited persistence of CAR-T cells, and immunosuppression in the tumor microenvironment. CAR-T cell exhaustion is a major cause of relapse. Epigenetic modifications can regulate T cell activation, maturation and depletion; they can be applied to reduce T cell depletion, improve infiltration, and promote memory phenotype formation to reduce relapse after CAR-T cell therapy.

View Article and Find Full Text PDF

Biological nanopores offer a promising approach for single-molecule analysis of nucleic acids, peptides, and proteins. The work presented here introduces a biological nanopore formed by the self-assembly of complement component 9 (C9). This exceptionally large and cylindrical protein pore is composed of 20 ± 4 monomers of C9 resulting in a diameter of 10 ± 4 nm and an effective pore length of 13 nm.

View Article and Find Full Text PDF

Efflux pumps that transport antibacterial drugs out of bacterial cells have broad specificity, commonly leading to broad spectrum resistance and limiting treatment strategies for infections. It remains unclear how efflux pumps can maintain this broad spectrum specificity to diverse drug molecules while limiting the efflux of other cytoplasmic content. We have investigated the origins of this broad specificity using theoretical models informed by the experimentally determined structural and kinetic properties of efflux pumps.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!