GTP-Binding Protein alpha Subunits

**Definition:** The GTPase-containing subunits of heterotrimeric GTP-binding proteins. When dissociated from the heterotrimeric complex these subunits interact with a variety of second messenger systems. Hydrolysis of GTP by the inherent GTPase activity of the subunit causes it to revert to its inactive (heterotrimeric) form. The GTP-Binding protein alpha subunits are grouped into families according to the type of action they have on second messenger systems.

**Tree numbers:** - D08.811.277.040.330.300.200.100 - D12.776.157.325.332.100 - D12.776.476.338.200.100 - D12.776.543.325.100

**Synonyms:** - GTP-Binding Protein alpha Subunit - G-Protein alpha Subunit