Localizations of the septin Spn4 tagged with GFP and mEGFP in fission yeast.

Septins are cytoskeletal proteins crucial for cell division and many other processes. In fission yeast, septins localize to the division site during septum formation. Recently, we conducted a study that elucidates the localizations and functionalities of epitope-tagged septins. However, some questions remain outstanding. Here we assessed the impacts of monomeric mEGFP and dimeric GFP(S65T) on the septin Spn4 tagged at either of its terminus. We found that septin levels were important for its function, Spn4-mEGFP localized normally to the division site, but GFP(S65T)-Spn4 formed elongated structures ectopically, further highlighting that dimeric tags are more disruptive to septin localizations.