A guanylate cyclase activator (or "GUCA") is one of group of proteins which upregulates guanylate cyclase.
It is also known as guanylate cyclase-activating protein, with the abbreviation "GCAP".
Mutations can be associated with vision defects.
There are five genes involved:
- GUCA1A, GUCA1B, GUCA1C
- GUCA2A, GUCA2B