Heterotrimeric G proteins are not the only guanine nucleotide-binding proteins. Which of the following represents a family of GTP-binding proteins that act as monomers rather than heterotrimeric compounds?

Question

Quizplus · Accepted Answer

Ras proteins are monomeric GTPases, meaning they function as single units rather than forming heterotrimeric complexes. ERK (extracellular signal-regulated kinase), Raf (rapidly accelerating fibrosarcoma), and Smad (intracellular signaling molecules) are all involved in signal transduction pathways but they are not known for their GTP-binding properties.

Heterotrimeric G Proteins Are Not the Only Guanine Nucleotide-Binding Proteins