Multiple 5′-splice variants of the rat glutamate transporter-1

In most brain areas, uptake of extracellular glutamate predominantly occurs through the glutamate transporter subtype, glutamate transporter-1 (GLT-1), which is enriched in astroglia. Here, we report the identification of five splice variants of the 5′-leader sequence of rat GLT-1 which contain varying numbers of upstream open reading frames and encode putative GLT-1 proteins with two distinct N-terminal modifications. We further demonstrate that the identified rat 5′-GLT-1 splice variants are expressed in a brain region-specific manner. Our findings point to potential influences of RNA splicing on glial glutamate transport in the intact and injured rat brain.