Secretion and function of Cln5 during the early stages of Dictyostelium development

In this study, we generated an antibody against Cln5 to show that the endogenous protein is secreted during the early stages of Dictyostelium development. Like human CLN5, the Dictyostelium homolog is glycosylated and requires this post-translational modification for secretion. Cln5 secretion bypasses the Golgi complex, and instead, occurs via an unconventional pathway linked to autophagy. Interestingly, we observed co-localization of Cln5 and GFP-Cln3 as well as increased secretion of Cln5 and Cln5-GFP in cln3− cells. Loss of Cln5 causes defects in adhesion and chemotaxis, which intriguingly, has also been reported for Dictyostelium cells lacking Cln3. Finally, autofluorescence was detected in cln5− cells, which is consistent with observations in mammalian systems. Together, our data support a function for Cln5 during the early stages of multicellular development, provides further evidence for the molecular networking of NCL proteins, and provides insight into the mechanisms that may underlie CLN5 function in humans.Graphical abstract
Source: Biochimica et Biophysica Acta (BBA) Molecular Cell Research - Category: Molecular Biology Source Type: research