GluA2lacking

GluA2lacking refers to a naturally occurring splice variant of the AMPA receptor subunit GluA2. AMPA receptors are ionotropic glutamate receptors that play a crucial role in excitatory neurotransmission in the central nervous system. The GluA2 subunit is a critical component of AMPA receptors, and its inclusion or exclusion, as well as its editing status, significantly influences the receptor's properties, particularly its calcium permeability.

The standard GluA2 subunit undergoes RNA editing at a specific site within the Q/R site, which is located in the pore-forming region of the channel. This editing event converts a glutamine (Q) codon to an arginine (R) codon. The presence of arginine at this position renders the GluA2 subunit impermeable to calcium ions. Consequently, AMPA receptors containing the edited GluA2 subunit (GluA2(R)) are calcium-impermeable.

The GluA2lacking splice variant, in contrast, lacks a portion of the exon encoding the Q/R site. Therefore, it cannot undergo the Q/R site editing process. This means that GluA2lacking subunits, when incorporated into AMPA receptors, result in receptors that are permeable to calcium ions, similar to receptors containing the unedited GluA2(Q) subunit.

The presence and function of GluA2lacking have been investigated in various neuronal populations and under different physiological and pathological conditions. Its contribution to neuronal excitability and calcium homeostasis is an area of ongoing research, with potential implications for understanding neurological disorders characterized by altered glutamatergic signaling and calcium dysregulation.