Judged: two independent readers; copy check clear.
cyclic GMP
cyclic GMP Cyclic GMP is a guanine-containing nucleotide with a phosphate group linked to the sugar at both the 3' and 5' positions.
Cyclic GMP is a guanine-containing nucleotide with a phosphate group linked to the sugar at both the 3' and 5' positions. In cells, it acts as a regulatory signal, often serving as a second messenger whose levels rise in response to some hormones and which can activate specific protein kinases.