The calcitonin gene can encode either the hormone calcitonin…
The calcitonin gene can encode either the hormone calcitonin or a protein called calcitonin-gene-related peptide depending on which 3′ cleavage site is used. In the thyroid gland, cleavage and polyadenylation occur after the fourth exon leading to calcitonin production. However, in the brain, the exact same transcript is cleaved after the sixth exon yielding calcitonin-gene-related peptide. This is possible because of a process known as: