Nitrogen permease regulator 2-like protein (NPRL2) (NPRL2)

Nitrogen permease regulator-like 2 (NPRL2), also known as tumor suppressor candidate 4 (TUSC4), is a critical protein component of the GATOR1 complex, which serves as a negative regulator of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway (1.1.1, 1.3.2). It functions as a GTPase-activating protein (GAP) for Rag GTPases, effectively inhibiting mTORC1 activity in response to amino acid deprivation (1.1.2, 1.3.1). In oncology, NPRL2 is recognized as a potent tumor suppressor; its downregulation or loss is associated with various malignancies, including non-small cell lung cancer and renal cell carcinoma, leading to uncontrolled cell growth and resistance to chemotherapies like cisplatin (1.2.3, 1.3.4). Conversely, germline or somatic mutations in the NPRL2 gene are linked to neurological disorders such as familial focal epilepsy and focal cortical dysplasia, where mTORC1 hyperactivation disrupts neuronal development and excitability (1.2.2, 1.4.1). Therapeutic strategies targeting NPRL2 include gene therapy to restore its expression in cancer cells, thereby inducing apoptosis and enhancing chemosensitivity (1.2.1, 1.5.1). Additionally, pharmacological mTOR inhibitors like rapamycin are employed to mitigate the pathological effects of NPRL2 deficiency in epilepsy and other mTORopathies (1.4.3).

Other names

Tumor suppressor candidate 4TUSC4NPR2NPR2LG21Gene 21 proteinFFEVF2GATOR1 complex subunit NPRL2

NPRL2 functions as a negative regulator of the mTORC1 pathway by acting as a GTPase-activating protein for Rag GTPases; therapeutic approaches include restoring its expression via gene therapy to suppress tumor growth or using mTOR inhibitors to counteract the effects of its loss in epilepsy.