Tspan2: a tetraspanin protein involved in oligodendrogenesis and cancer metastasis

Abstract

Tetraspanin 2 (Tspan2) is one of the less well-characterised members of the tetraspanin superfamily, and its precise function in different human tissue types remains to be explored. Initial studies have highlighted its possible association in neuroinflammation and carcinogenesis. In the central nervous system, Tspan2 may contribute to the early stages of the oligodendrocyte differentiation into myelin-forming glia. Furthermore, in human lung cancer, Tspan2 could be involved in the progression of the tumour metastasis by modulating cancer cell motility and invasion functions. In this review, we discuss the available evidence for the potential role of Tspan2 and introduce possible strategies for disease targeting.

Keywords: TEMs; Tspan2; metastasis; oligodendrocytes; tetraspanin 2; transmembrane proteins.

Figure 1.. Prediction of Tspan2 secondary structure.

The predicted disulphide bonds between the CCG motif and the other two cysteines in the EC2 region are highlighted with red colour bonds. The seven tyrosines are illustrated with yellow colour, whereas the blue colour is the potential glycosylation site at asparagine 139. The aa arrangement and their topological hydrophobicity/hydrophilicity are extracted from the UniProt database, accession number: UniProtKB — O60636 (TSN2_HUMAN). PM: plasma membrane; EC1: extracellular domain 1; EC2: extracellular domain 2; TM: transmembrane.

Figure 2.. Tspan2 protein sequence alignment and dendrogram.

(a) The protein sequence alignment of human Tspan2 along with CD9 and CD81. The bar graph represents the conservation percentages between each single aa of the concerned tetraspanins. (b) The tree phylogeny of human Tspan2, CD9 and CD81 based on their protein sequence alignment. The phylogram constructed by the RapidNJ plugin, and the Juke-Cantor evolution model used for distance calculation. Scale bar indicates the branch length. All the analysis was performed on CLC Sequence Viewer platform version 7.7.1 (QIAGEN, Aarhus, Denmark).