Clues to crustacean hormone production

Many hormones are small proteins that are cut from inactive precursor proteins by enzymes. This mechanism is well understood in vertebrates, but not in crustaceans.

Crustacean hyperglycemic hormone (CHH) is a small protein that regulates glucose metabolism. In one species of crayfish, tissue that expresses CHH also expresses an enzyme called PC2, which processes hormone precursors in vertebrates; this indicates a similar mechanism in crustaceans. Kallaya Sritunyalucksana and her colleagues at the National Center for Genetic Engineering and Biotechnology in Thailand have now found evidence for this in shrimp¹.

By characterizing a PC2-like enzyme called PmPC2 from the giant tiger shrimp, Penaeus monodon, the researchers observed that its structure is similar to vertebrate PC2 versions and it is mainly expressed in hormone-producing tissue. PmPC2 also binds directly to CHH and to 7B2, a known PC2-interacting protein in other animals. Together, these findings suggested a role for PmPC2 in hormone production similar to that in vertebrates.

The next step is to directly demonstrate this function. “We would like to show that PmPC2 is involved in the maturation of shrimp endocrine hormones,” says Sritunyalucksana.

“Shrimp aquaculture is one major exporting industry of many Asian countries. Understanding shrimp endocrinology will be an advantage for improvement of growth performance and selective breeding programs.”