Dynamin 2 interacts with connexin 26 to regulate its degradation and function in gap junction formation

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Connexin 26 (Cx26) is crucial for gap junctional intercellular communication (GJIC) and development.
• Cx26 deregulation, often due to mutations, is linked to congenital deafness.
• Mechanisms regulating Cx26 protein levels are not fully understood.

Purpose of the Study:

• To identify novel interactors of Connexin 26 (Cx26).
• To elucidate the role of identified interactors in Cx26 regulation and function.
• To investigate the molecular mechanisms governing Cx26 protein levels and GJIC.

Main Methods:

• Yeast and mammalian cell interaction studies to identify Cx26 binding partners.
• Deletion studies to map interaction domains between Cx26 and dynamin 2 (Dyn2).
• siRNA and pharmacological inhibition (dynasore) of Dyn2 to assess its effect on Cx26.
• Analysis of Cx26 degradation, endocytosis, ubiquitination, and GJIC.

Main Results:

• Dynamin 2 (Dyn2) was identified as a Cx26 interactor in both yeast and mammalian cells.
• The C-terminus of Cx26 and the GTPase effector domain of Dyn2 mediate their interaction.
• Dyn2 inhibition reduced Cx26 degradation at the plasma membrane and altered GJIC.
• Dyn2 was shown to regulate Cx26 endocytosis and ubiquitination.

Conclusions:

• Dynamin 2 (Dyn2) is a key binding partner of Connexin 26 (Cx26).
• Dyn2 plays a critical role in regulating Cx26 endocytosis, degradation, and ubiquitination.
• Dyn2 is involved in controlling gap junctional intercellular communication (GJIC) through its interaction with Cx26.