Details

Autor(en) / Beteiligte

• Raunser, Stefan
• Haase, Winfried
• Franke, Cornelia
• Eckert, Gunter P
• Müller, Walter E
• Kühlbrandt, Werner

Titel

Heterologously expressed GLT-1 associates in approximately 200-nm protein-lipid islands

Ist Teil von

• Biophysical journal, 2006-11, Vol.91 (10), p.3718-3726

Ort / Verlag

United States

Erscheinungsjahr

2006

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• The glutamate transporter GLT-1 from Rattus norvegicus was expressed at high level in baby hamster kidney (BHK-21) cells by the Semliki Forest Virus expression system. We examined the expressed GLT-1 in the plasma membrane and found that the transporter accumulates in detergent-insoluble lipid-protein assemblies. Freeze-fracture, immunogold labeling, and electron microscopy revealed that GLT-1 forms approximately 200-nm protein-rich islands in the plasma membrane. Cholesterol depletion in living cells resulted in a dispersion of the GLT-1 islands, indicating that they are the result of lipid-protein rather than protein-protein interactions. Disruption of GLT-1 islands and dispersion of GLT-1 goes along with a reduction of the glutamate transport activity. Our direct visualization of lipid-protein islands in the plasma membrane of tissue culture cells suggests that the reported clustering of glutamate transporters and their cholesterol-dependent transport activity in cells is likewise connected to their association with cholesterol-rich microdomains in the plasma membrane.