Figure 1. Co-staining of TNFRSF14 (green) with a Rods & Rings marker protein (red) and DAPI (blue) in U-2 OS cells. Overlapping regions appear yellow.

This week we highlight a new structure in the Cell Atlas available in version 16 thanks to the annotations done by citizen scientists in Project Discovery, a mini game within EVE Online. Rods & Rings.

As the name describes, these unique structures that form large rod and ring type aggregates in the cytoplasm that look a bit like sprinkles. Little is known about this structure and the proteins that are involved in it. In fact, it wasn't until 2011 when the term "Rods & Rings" was coined (Seeling HP et al. 2011,Carcamo WC et al. 2011).

Although we are a long way from understanding Rods & Rings, it was quickly discovered that these structures appeared in Hepatitis C patients and were inducible via treatment with ribavirin, a common drug used in the treatment of Hepatitis C (Covini G et al. 2012).

Further research has gone on to show that these structures may be related to how the cell processes energy, with the most well known member of this structure being inosine monophosphate dehydrogenase (IMPDH). This enzyme allows for the production of GTP, a molecule used for energy in the cell.

Previously only a handful of proteins are known to localize to the Rods & Rings, however thanks to the work of citizen scientists in Project Discovery we have managed to identify several novel candidates as belonging to this cellular structure. To date, 18 genes have been confirmed via co-localization assays with a marker protein for Rods & Rings. Today we highlight Tumor necrosis factor receptor superfamily, member 14 TNFRSF14, a protein from the tumor necrosis factor family. Here we show a co-staining for TNFRSF14 (green) with a Rods & Rings marker protein (red) in U-2 OS cells. Ribavirin was used to induce the formation of rods and rings.