Cloning and sequencing of the equine testicular follitropin receptor.

This research investigates the structure of the equine follitropin receptor, found in horse testes, using a technique called RACE-PCR to clone the receptor. The study found that this receptor shares a significant resemblance to similar receptors in other mammals, but has 10 different amino acids in the extracellular domain and contains a unique N-glycosylation site, not found in the other receptors.

Cloning and Sequencing

• The researchers used the RACE-PCR technique for cloning the equine follitropin receptor (eFSHR). The main objective was to investigate whether specific structural elements within the eFSHR are the reason for the enhanced distinctiveness of this receptor compared to other FSH receptors.

Sequence Analysis

• After cloning, the team conducted a sequence analysis of the eFSHR. They found that the structure closely resembles FSH receptors in other mammals.
• However, they also found 10 unique substitution of amino acid residues in the eFSHR’s extracellular domain. The extracellular domain is the portion of the protein that is located outside of the cell and it often plays a major role in receptor protein interactions.

N-glycosylation Site

• Upon further analysis, a potential N-glycosylation site was discovered in the eFSHR. This site did not align with the positions of N-glycosylation sites in other follitropin receptors.
• N-glycosylation is a biological process where sugars are added to proteins. This process is essential in protein folding and stability, and influences protein interactions. The unique position of this site in eFSHR might affect its functionality and specificity.

Northern Blot Analysis

• A Northern blot analysis was performed to examine the transcripts in horse testis.
• Three different lengths of transcripts, specifically 4.2 kb, 2.3 kb, and 1.0 kb, were identified. This could indicate different isoforms or forms of the follitropin receptor found in the horse testis.