EpCAM (epithelial cell adhesion molecule, also known as Trop-1) and Trop-2 (also known as tumor-associated calcium signal transducer 2, TACSTD2) are transmembrane glycoproteins that belong to the tumour-associated calcium signal transducer (TACSTD) family. They are evolutionarily related and both are implicated in signaling triggered by proteolytic cleavage within the ectodomain [1,3]. They share an overall similar structure but differ in their dimers formation. They consist of an ectodomain with an N-terminal, thyroglobulin type-1 (TY, Pfam:PF00086) and C-terminal domains. This entry represents the C-terminal domain of EpCAM and Trop-2, which has an alpha+beta fold [1-3].

1: Crystal structure and its bearing towards an understanding of key biological functions of EpCAM. Pavsic M, Guncar G, Djinovic-Carugo K, Lenarcic B; Nat Commun. 2014;5:4764. PMID:25163760

2: MM-131, a bispecific anti-Met/EpCAM mAb, inhibits HGF-dependent and HGF-independent Met signaling through concurrent binding to EpCAM. Casaletto JB, Geddie ML, Abu-Yousif AO, Masson K, Fulgham A, Boudot A, Maiwald T, Kearns JD, Kohli N, Su S, Razlog M, Raue A, Kalra A, Hakansson M, Logan DT, Welin M, Chattopadhyay S, Harms BD, Nielsen UB, Schoeberl B, Lugovskoy AA, MacBeath G; Proc Natl Acad Sci U S A. 2019;116:7533-7542. PMID:30898885

3: Trop2 Forms a Stable Dimer with Significant Structural Differences within the Membrane-Distal Region as Compared to EpCAM. Pavsic M; Int J Mol Sci. 2021; [Epub ahead of print] PMID:34638982