TLR Stimulation Produces IFN-β as the Primary Driver of IFN Signaling in Nonlymphoid Primary Human Cells.

Several human autoimmune diseases are characterized by increased expression of type 1 IFN-stimulated genes in both the peripheral blood and tissue. The contributions of different type I IFNs to this gene signature are uncertain as the type I IFN family consists of 13 alphas and one each of β, ε, κ, and ω subtypes. We sought to investigate the contribution of various IFNs to IFN signaling in primary human cell types.

Co-inhibitory T cell receptor KLRG1: human cancer expression and efficacy of neutralization in murine cancer models.

Background: KLRG1 is a lymphocyte co-inhibitory, or immune checkpoint, receptor expressed predominantly on late-differentiated effector and effector memory CD8+ T and NK cells. Targeting of KLRG1 neutralization in murine cancer models has not previously been reported.

Methods: We studied KLRG1 expression in human blood and tumor samples from available genomic datasets.

Designed BH3 peptides with high affinity and specificity for targeting Mcl-1 in cells.

Mcl-1 is overexpressed in many cancers and can confer resistance to cell-death signaling in refractory disease. Molecules that specifically inhibit Mcl-1 hold potential for diagnosing and disrupting Mcl-1-dependent cell survival. We selected three peptides from a yeast-surface display library that showed moderate specificity and affinity for binding to Mcl-1 over Bfl-1, Bcl-xL, Bcl-2, and Bcl-w.

In silico and in vitro elucidation of BH3 binding specificity toward Bcl-2.

Interactions between Bcl-2-like proteins and BH3 domains play a key role in the regulation of apoptosis. Despite the overall structural similarity of their interaction with helical BH3 domains, Bcl-2-like proteins exhibit an intricate spectrum of binding specificities whose underlying basis is not well understood. Here, we characterize these interactions using Rosetta FlexPepBind, a protocol for the prediction of peptide binding specificity that evaluates the binding potential of different peptides based on structural models of the corresponding peptide-receptor complexes.

Synthesis of a spin-labeled anti-estrogen as a dynamic motion probe for the estrogen receptor ligand binding domain.

The preparation and characterization of a novel nitroxide spin probe based on a steroidal anti-estrogen is described. The probe 5 demonstrated very high binding affinity for both the alpha and beta isoforms of the estrogen receptor-ligand binding domain. EPR spectrometric studies demonstrate conformational constraints for the ligand, consistent with the nitroxyl moiety occupying a position just beyond the receptor-solvent interface.

Determinants of BH3 binding specificity for Mcl-1 versus Bcl-xL.

Interactions among Bcl-2 family proteins are important for regulating apoptosis. Prosurvival members of the family interact with proapoptotic BH3 (Bcl-2-homology-3)-only members, inhibiting execution of cell death through the mitochondrial pathway. Structurally, this interaction is mediated by binding of the alpha-helical BH3 region of the proapoptotic proteins to a conserved hydrophobic groove on the prosurvival proteins.

Mcl-1-Bim complexes accommodate surprising point mutations via minor structural changes.

Mcl-1 is an antiapoptotic Bcl-2-family protein that protects cells against death. Structures of Mcl-1, and of other anti-apoptotic Bcl-2 proteins, reveal a surface groove into which the alpha-helical BH3 regions of certain proapoptotic proteins can bind. Despite high overall structural conservation, differences in this groove afford binding specificity that is important for the mechanism of Bcl-2 family function.

Dynamic conformational responses of a human cannabinoid receptor-1 helix domain to its membrane environment.

The influence of membrane environment on human cannabinoid 1 (hCB(1)) receptor transmembrane helix (TMH) conformational dynamics was investigated by solid-state NMR and site-directed spin labeling/EPR with a synthetic peptide, hCB(1)(T377-E416), corresponding to the receptor's C-terminal component, i.e., TMH7 and its intracellular alpha-helical extension (H8) (TMH7/H8).

Molecular-scale force measurement in a coiled-coil peptide dimer by electron spin resonance.

A new method for measuring forces between small protein domains based on double electron-electron resonance (DEER) spectroscopy is demonstrated using a model peptide derived from the alpha-helical coiled-coil leucine zipper of yeast transcriptional activator GCN4. The equilibrium distribution of distances between two nitroxide spin labels rigidly attached to the helices of the dimer was determined by DEER and yielded a closing force of 100 +/- 10 pN between monomers, in excellent agreement with theoretical predictions.