5EJC, 4Z6Y724864930ENSG00000165699ENSMUSG00000026812Q92574Q9EP53NM_000368NM_001008567NM_001162426NM_001162427NM_001362177NM_022887NM_001289575NM_001289576NP_000359NP_001155898NP_001155899NP_001349106NP_001276504NP_001276505NP_075025Tuberous sclerosis 1 (TSC1), also known as hamartin, is a protein that in humans is encoded by the TSC1 gene.

TSC1 functions as a facilitator of Hsp90 in chaperoning the kinase and non-kinase clients including TSC2, therefore preventing their ubiquitination and degradation in the proteasome.

This complex negatively regulates mTORC1 signaling by functioning as a GTPase-activating protein (GAP) for the small GTPase Rheb, an essential activator of mTORC1.

Defects in this gene can cause tuberous sclerosis, due to a functional impairment of the TSC complex.

[citation needed] TSC1 may be involved in protecting brain neurons in the CA3 region of the hippocampus from the effects of stroke.