Quantitative characterization of tetraspanin 8 homointeractions in the plasma membrane

Daniel Wirth, Ece Özdemir, Christopher King, Lena Ahlswede, Dirk Schneider, Kalina Hristova

Research output: Contribution to journalArticlepeer-review


The spatial distribution of proteins in cell membranes is crucial for signal transduction, cell communication and membrane trafficking. Members of the Tetraspanin family organize functional protein clusters within the plasma membrane into so-called Tetraspaninenriched microdomains (TEMs). Direct interactions between Tetraspanins are believed to be important for this organization. However, studies thus far have utilized mainly coimmunoprecipitation methods that cannot distinguish between direct and indirect, through common partners, interactions. Here we study Tetraspanin 8 homointeractions in living cells via quantitative fluorescence microscopy. We demonstrate that Tetraspanin 8 exists in a monomer-dimer equilibrium in the plasma membrane. Tetraspanin 8 dimerization is described by a high dissociation constant (Kd = 14 700 ± 1100 Tspan8/mm2), one of the highest dissociation constants measured for membrane proteins in live cells. We propose that this high dissociation constant, and thus the short lifetime of the Tetraspanin 8 dimer, is critical for Tetraspanin 8 functioning as a master regulator of cell signaling.

Original languageEnglish (US)
Pages (from-to)3643-3654
Number of pages12
JournalBiochemical Journal
Issue number19
StatePublished - Oct 2021

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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