Human V-ATPase function is positively and negatively regulated by TLDc proteins

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Proteins with the conserved TLDc domain are crucial for cellular protection against oxidative stress and are linked to neurological health and disease.
• The precise mechanisms by which TLDc proteins function remain largely unknown.
• Previous studies showed yeast Oxr1p inhibits vacuolar ATPase (V-ATPase) by promoting its disassembly.

Purpose of the Study:

• To investigate the direct impact of five human TLDc proteins (TLDC2, NCOA7, OXR1, TBC1D24, and mEAK7) on the activity of the human V-ATPase.
• To elucidate the role of TLDc proteins in the regulation of V-ATPase function in mammals.

Main Methods:

• Assaying the activity of purified human V-ATPase in the presence of different human TLDc proteins.
• Analyzing the effect of TLDc proteins on V-ATPase assembly and disassembly using biochemical techniques.
• Comparing the functional outcomes of TLDc protein interactions with V-ATPase.

Main Results:

• TLDC2, TBC1D24, and the TLDc domains of OXR1 and NCOA7 were found to inhibit human V-ATPase activity by inducing enzyme disassembly.
• Conversely, mEAK7 was identified as an activator of human V-ATPase activity.
• These findings demonstrate differential regulation of V-ATPase by various human TLDc proteins.

Conclusions:

• Mammalian TLDc proteins exhibit diverse regulatory effects on V-ATPase activity, including both inhibition and activation.
• The study provides novel insights into the mechanisms of V-ATPase regulation by the TLDc protein family.
• Understanding these interactions is critical for elucidating the role of TLDc proteins in neurological health and disease.