Gem nuclear organelle-associated protein 2 (GEMIN2)

Gem nuclear organelle-associated protein 2 (GEMIN2) is an essential, highly conserved protein that forms a core component of the survival of motor neuron (SMN) complex, which catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs)—critical building blocks of the spliceosome, responsible for pre-mRNA splicing[2][3][7]. GEMIN2 directly binds a pentamer of Sm proteins (SmD1/D2/F/E/G) and, together with SMN, stabilizes and positions these proteins to ensure accurate and specific snRNP assembly, partly by preventing non-cognate RNA binding through negative cooperativity mechanisms[1][2]. Structural studies reveal that GEMIN2 “wraps” around the Sm protein pentamer, gripping it and helping serve as a checkpoint in the selective recruitment of RNA and further Sm core assembly, thereby ensuring quality control in spliceosomal complex formation[1][2][3][5]. While not a classical receptor, enzyme, or direct therapeutic target, defects or mutations in the SMN–GEMIN2 interaction—especially in the context of mutations in SMN—are linked to the pathogenesis of spinal muscular atrophy, the leading hereditary cause of infant mortality[2][4][7]. GEMIN2 is essential for viability, with knockout studies in mice resulting in embryonic lethality, possibly earlier than SMN knockout[2][4]. Currently, no drugs directly target GEMIN2, nor are there standard biomarkers or safety concerns specific to it in a therapeutic context.

Other names

Gem-associated protein 2SIP1Gemin-2SMN-interacting protein 1Component of gems 2Survival of motor neuron protein-interacting protein 1SIP1-deltaSMN interacting protein 1-delta