Spotlights on Recent JACS Publications

■ NEW INSIGHTS INTO CHAPERONES UNCOVERED In the tightly woven ever-shifting environment of the chromosome, getting proteins to fold correctly and find their binding partners is critical. That is where chaperones come in. Garegin Papoian, Yamini Dalal, and colleagues perform molecular dynamics simulations and in vivo experiments investigating the interactions between the centromere-specific chaperone, Holliday Junction Recognition Protein (HJURP), and histone proteins, which manage genetic material in human chromosomes (DOI: 10.1021/jacs.6b05355). Their findings suggest that chaperones not only facilitate folding but also can promote correct interactions between histones themselves. Centromere protein A (CENP-A), a centromere-specific variant of canonical histone 3, is essential for mitosis and centromere packing. The researchers are curious about the roles the chaperone HJURP plays in the interaction between key histone proteins, which might contribute to its unique biological function. Their molecular simulations and experiments indicate that HJUR, while potentially serving as a protein-folding chaperone, can also help CENP-A associate with its binding partners, which guarantees the stability of the binding without disruption from other factors. This study allows for general predictions about histone−histone interactions, and provides new insights into the underlying mechanisms governing the HJURP-mediated assembly of CENP-A nucleosomes in vivo. Erika Gebel Berg, Ph.D.