Peptide Ligands for Pro-survival Protein Bfl-1 from Computationally Guided Library Screening

Pro-survival members of the Bcl-2 protein family inhibit cell death by binding short helical BH3 motifs in pro-apoptotic proteins. Mammalian pro-survival proteins Bcl-x[subscript L], Bcl-2, Bcl-w, Mcl-1, and Bfl-1 bind with varying affinities and specificities to native BH3 motifs, engineered peptides, and small molecules. Biophysical studies have determined interaction patterns for these proteins, particularly for the most-studied family members Bcl-x[subscript L] and Mcl-1. Bfl-1 is a pro-survival protein implicated in preventing apoptosis in leukemia, lymphoma, and melanoma. Although Bfl-1 is a promising therapeutic target, relatively little is known about its binding preferences. We explored the binding of Bfl-1 to BH3-like peptides by screening a peptide library that was designed to sample a high degree of relevant sequence diversity. Screening using yeast-surface display led to several novel high-affinity Bfl-1 binders and to thousands of putative binders identified through deep sequencing. Further screening for specificity led to identification of a peptide that bound to Bfl-1 with K[subscript d] < 1 nM and very slow dissociation from Bfl-1 compared to other pro-survival Bcl-2 family members. A point mutation in this sequence gave a peptide with ~50 nM affinity for Bfl-1 that was selective for Bfl-1 in equilibrium binding assays. Analysis of engineered Bfl-1 binders deepens our understanding of how the binding profiles of pro-survival proteins differ and may guide the development of targeted Bfl-1 inhibitors.National Institute of General Medical Sciences (U.S.) (Award GM084181)National Institute of General Medical Sciences (U.S.) (Award P50-GM68762

Indigenous Children’s Language Practices in Australia

While the documentation of Australian Aboriginal and Torres Strait Islander languages has attracted considerable research attention, the use of these languages by children has only recently emerged as a field of research. Building on the small number of early studies of these children’s language acquisition, development, and practices, we review the now considerable variety of studies which have explored Australian Aboriginal children’s early language learning environments and processes. In this ecologically complex linguistic environment, studies investigate children’s acquisition of some remaining traditional languages—often in multilingual contexts, child-directed speech styles and practices, and the development of new and emerging contact languages—both mixed languages and creoles, and the ways that children and young people are altering and innovating the language ecologies. The studies focus particularly on those children who are being raised in remote settings where, while English is taught in school, it is neither the language the children learn as their first language nor the language of the community in which the children live