Signal recognition particle receptor subunit alpha

SRPRA (signal recognition particle receptor subunit alpha, also known as SR-alpha) is a 638-amino-acid component of the signal recognition particle receptor complex (UniProt: P08240). It functions as a guanosine triphosphate-dependent binding partner for SRP54, facilitating the recognition and targeting of nascent secretory proteins to the endoplasmic reticulum membrane during translation (UniProt: P08240).

SRPRA operates within the broader signal recognition particle machinery, which directs cotranslational protein translocation. Its activity is essential for proper secretory pathway routing and involves GTPase-mediated conformational changes that enable protein translocation into the ER lumen (UniProt: P08240). The protein is widely expressed across human tissues supporting protein secretion.

SRPRA is classified as SFARI Category 1 (SFARI Cat 1), indicating a high-confidence autism spectrum disorder risk gene. This classification suggests evidence of de novo or inherited mutations in autism cases, though specific mechanistic links to neurodevelopmental phenotypes remain to be fully characterized.