This is a family of proteins from the CLN3 gene. A mis-sense mutation of glutamic acid (E) to lysine (K) at position 295 in the human protein (Swiss:Q13286) has been implicated in Juvenile neuronal ceroid lipofuscinosis (Batten disease) [1]. Batten disease is characterised by the accumulation of autofluorescent material in the lysosomes of most cells. Members of this family are transmembrane proteins functional in pre-vacuolar compartments. The protein in Sch.pombe is found to be localised to the vacuolar membrane, and a lack of functional protein clearly affects the size and pH of the vacuole. Thus the protein is necessary for vacuolar homeostasis [2]. It is important for localisation of late endosomal/lysosomal compartments, and it interacts with motor components driving both plus and minus end microtubular trafficking: tubulin, dynactin, dynein and kinesin-2 [3].

1: Molecular screening of Batten disease: identification of a missense mutation (E295K) in the CLN3 gene. Zhong N, Wisniewski KE, Kaczmarski AL, Ju W, Xu WM, Xu WW, Mclendon L, Liu B, Kaczmarski W, Sklower Brooks SS, Brown WT; Hum Genet 1998;102:57-62. PMID:9490299

2: btn1, the Schizosaccharomyces pombe homologue of the human Batten disease gene CLN3, regulates vacuole homeostasis. Gachet Y, Codlin S, Hyams JS, Mole SE; J Cell Sci. 2005;118:5525-5536. PMID:16291725

3: Neuronal ceroid lipofuscinosis protein CLN3 interacts with motor proteins and modifies location of late endosomal compartments. Uusi-Rauva K, Kyttala A, van der Kant R, Vesa J, Tanhuanpaa K, Neefjes J, Olkkonen VM, Jalanko A; Cell Mol Life Sci. 2012;69:2075-2089. PMID:22261744