Filopodial protrusion driven by density-dependent Ena-TOCA-1 interactions.

Filopodia are narrow actin-rich protrusions with important roles in neuronal development where membrane-binding adaptor proteins, such as I-BAR- and F-BAR-domain-containing proteins, have emerged as upstream regulators that link membrane interactions to actin regulators such as formins and proteins of the Ena/VASP family. Both the adaptors and their binding partners are part of diverse and redundant protein networks that can functionally compensate for each other. To explore the significance of the F-BAR domain-containing neuronal membrane adaptor TOCA-1 (also known as FNBP1L) in filopodia we performed a quantitative analysis of TOCA-1 and filopodial dynamics in Xenopus retinal ganglion cells, where Ena/VASP proteins have a native role in filopodial extension. Increasing the density of TOCA-1 enhances Ena/VASP protein binding in vitro, and an accumulation of TOCA-1, as well as its coincidence with Ena, correlates with filopodial protrusion in vivo. Two-colour single-molecule localisation microscopy of TOCA-1 and Ena supports their nanoscale association. TOCA-1 clusters promote filopodial protrusion and this depends on a functional TOCA-1 SH3 domain and activation of Cdc42, which we perturbed using the small-molecule inhibitor CASIN. We propose that TOCA-1 clusters act independently of membrane curvature to recruit and promote Ena activity for filopodial protrusion.

Harmonious naming across nomenclature codes exemplified by the description of bacterial isolates from the mammalian gut.

A dual system for naming prokaryotes is currently in place based on the well-established International Code of Nomenclature of Prokaryotes (ICNP) and the newly created Code of Nomenclature of Prokaryotes Described from Sequence Data (SeqCode). Whilst recent creation of the SeqCode opened an avenue to accelerate the naming of uncultured taxa, the existence of two codes increases the risk of species being assigned multiple validly published names. In this work we present a workflow that aims to limit conflicts by firstly naming novel cultured taxa under the SeqCode, and secondly under the ICNP, enhancing the traceability of the taxa across the two codes. To exemplify this workflow, we describe four novel taxa isolated from the intestine of pigs: Intestinicryptomonas porci gen. nov., sp. nov. (strain CLA-KB-P66T, genome accession GCA_033971905.1TS) within a novel family, Intestinicryptomonaceae; Grylomicrobium aquisgranensis gen. nov., sp. nov. (CLA-KB-P133T, GCA_033971865.1TS); Absicoccus intestinalis sp. nov. (CLA-KB-P134T, GCA_033971885.1TS); and Mesosutterella porci sp. nov. (oilRF-744- wt-GAM-9T, GCF_022134585.1TS).