Structural impact on SARS-CoV-2 spike protein by D614G substitution.

Substitution for aspartic acid (D) by glycine (G) at position 614 in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appears to facilitate rapid viral spread. The G614 strain and its recent variants are now the dominant circulating forms. Here, we report cryo-electron microscopy structures of a full-length G614 S trimer, which adopts three distinct prefusion conformations that differ primarily by the position of one receptor-binding domain.

Cooperative adaptation to therapy (CAT) confers resistance in heterogeneous non-small cell lung cancer.

Understanding intrinsic and acquired resistance is crucial to overcoming cancer chemotherapy failure. While it is well-established that intratumor, subclonal genetic and phenotypic heterogeneity significantly contribute to resistance, it is not fully understood how tumor sub-clones interact with each other to withstand therapy pressure. Here, we report a previously unrecognized behavior in heterogeneous tumors: cooperative adaptation to therapy (CAT), in which cancer cells induce co-resistant phenotypes in neighboring cancer cells when exposed to cancer therapy.

TGFβ promotes breast cancer stem cell self-renewal through an ILEI/LIFR signaling axis.

FAM3C/Interleukin-like EMT Inducer (ILEI) is an oncogenic member of the FAM3 cytokine family and serves essential roles in both epithelial-mesenchymal transition (EMT) and breast cancer metastasis. ILEI expression levels are regulated through a non-canonical TGFβ signaling pathway by 3'-UTR-mediated translational silencing at the mRNA level by hnRNP E1. TGFβ stimulation or silencing of hnRNP E1 increases ILEI translation and induces an EMT program that correlates with enhanced invasion and migration.

S. pombe Uba1-Ubc15 Structure Reveals a Novel Regulatory Mechanism of Ubiquitin E2 Activity.

Ubiquitin (Ub) E1 initiates the Ub conjugation cascade by activating and transferring Ub to tens of different E2s. How Ub E1 cooperates with E2s that differ substantially in their predicted E1-interacting residues is unknown. Here, we report the structure of S.

Cathepsin-B-mediated cleavage of Disabled-2 regulates TGF-β-induced autophagy.

Transforming growth factor-β (TGF-β) induces the expression of Disabled-2 (Dab2), an endocytic adaptor and tumour suppressor, concomitant with the induction of an epithelial-mesenchymal transition (EMT) in mammary epithelial cells. Here we show that following TGF-β-mediated EMT, sustained TGF-β treatment leads to proteolytic degradation of Dab2 by cathepsin B (CTSB), loss of the mesenchymal phenotype and induction of autophagy. CTSB inhibition or expression of a CTSB-resistant Dab2 mutant maintains Dab2 expression and shifts long-term TGF-β-treated cells from autophagy to apoptosis.

Biophysical characterization of naturally occurring titin M10 mutations.

The giant proteins titin and obscurin are important for sarcomeric organization, stretch response, and sarcomerogenesis in myofibrils. The extreme C-terminus of titin (the M10 domain) binds to the N-terminus of obscurin (the Ig1 domain) in the M-band. The high-resolution structure of human M10 has been solved, along with M10 bound to one of its two known molecular targets, the Ig1 domain of obscurin-like.