Self-assembled peptide–nanoparticle superstructures, with tuned architectures and/or functionalities, hold great promise in multiple high-end applications.

SummaryDuring sexual reproduction in the ciliate, Tetrahymena thermophila, cells of complementary mating type pair (“conjugate”) undergo simultaneous meiosis and fertilize each other. In both mating partners only one of the four meiotic products is “selected” to escape autophagy, and this nucleus divides mitotically to produce two pronuclei. The migrating pronucleus of one cell translocates to the mating partner and fuses with its stationary pronucleus and vice versa. Selection of the designated gametic nucleus was thought to depend on its position within the cell because it always attaches to the junction with the partner cell. Here we show that a transmembrane protein, Semi1, is crucial for attachment. Loss of Semi1 causes failure to attach and consequent infertility. However, a nucleus is selected and gives rise to pronuclei regardless of Semi1 expression, indicating that attachment of a nucleus to the junction is not a precondition for selection but follows the selection process.

Tyrosine nitration, a post‐translational modification (PTM) that takes place under nitrosative stress conditions, occurs through a non‐enzymatic peroxynitrite‐mediated reaction. Although protein nitration has long been considered an irreversible PTM involved in nitrosative stress‐associated diseases, it has also been suggested to be a regulatory mechanism of signal transduction. Therefore, the development of tools that help to understand this protein modification is of great interest. Herein, we explore a TbIII‐chelating metallopeptide to monitor tyrosine nitration. The luminescence of this probe decreases significantly between its non‐nitrated and nitrated states, and this reduction in the luminescence intensity is directly related to the degree of tyrosine nitration after treatment with peroxynitrite. Remarkably, the luminescence intensity changes after nitration are not affected in the presence of complex biological media, which makes it a promising tool for understanding this protein modification.