CGA
CGA (glycoprotein hormones, alpha polypeptide) encodes the alpha chain shared by the four human glycoprotein hormones TSH, LH, FSH and CG. It is a secreted subunit also known as HCG, GPHa, GPHA1, FSHA, LHA, TSHA and GPA1. Browse Assay Genie's current range of CGA research reagents below, or read on for the biology behind the target.
CGA provides the common alpha chain of the active heterodimeric glycoprotein hormones: thyrotropin (thyroid stimulating hormone, TSH), lutropin (luteinizing hormone, LH), follitropin (follicle stimulating hormone, FSH) and choriogonadotropin (CG). These hormones bind specific receptors on their target cells, which in turn activate downstream signalling pathways. The alpha subunit is therefore a component of several distinct endocrine signals rather than of a single hormone.
Each of the four hormones is a dimer of an alpha and a beta subunit associated noncovalently. The alpha subunits are identical across the hormones, whereas the beta chains are unique and confer biological specificity. The CGA protein is secreted and belongs to the glycoprotein hormones subunit alpha family. The HGNC places the gene in the groups of receptor ligands and glycoprotein hormone subunits. Researchers studying the CGA gene or the CGA protein often need to distinguish the free alpha subunit from the assembled heterodimers, which depends on which beta chain is paired with it.
According to the NCBI Gene summary, two transcript variants encoding different isoforms have been found for this gene. The symbol HCG appears among the aliases, reflecting the role of the alpha chain in chorionic gonadotropin, while FSHA, LHA and TSHA reflect its presence in the other three hormones. Mouse and rat both carry a Cga ortholog.
CGA is the alpha subunit of LH, FSH and CG, so it is relevant to studies of gonadotropin hormone composition and receptor signalling.
As the alpha chain of TSH, CGA contributes to the hormone that binds its receptor on target cells and activates downstream pathways.
Because the alpha chain is identical and the beta chain confers specificity, CGA is a reference point for studying alpha-beta subunit association.
Classified by HGNC as a receptor ligand subunit, CGA is used to explore how glycoprotein hormones engage specific receptors.
CGA encodes the alpha chain shared by TSH, LH, FSH and CG. These heterodimeric hormones bind specific receptors on target cells and activate downstream signalling pathways. The beta chain of each hormone, not the alpha chain, gives the biological specificity.
Because the same alpha subunit is part of four hormones, its aliases include HCG, FSHA, LHA and TSHA, along with GPHa, GPHA1 and GPA1. NCBI Gene reports two transcript variants encoding different isoforms for this gene.
Mouse and rat each have an ortholog named Cga, so the gene is present in common rodent models. Check the datasheet of any product for its validated reactivity before using it in a given species.
Other targets with similar gene symbols, listed here for navigation alongside glycoprotein hormone research.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P01215; product specifications from Assay Genie datasheets.