Fig.5.

Transporters and transport pathways for energy substrate movement across plasma and mitochondrial membranes. Key transporters involved in moving metabolites into CNS cells and mitochondria. Changes indicated have been reported in different HD model systems. The malate-aspartate shuttle crosses the IMM on the left. The carnitine shuttle that brings FA from the cytosol into the matrix is on the right. ST represents numerous substrate transporters across the IMM and OMM for pyruvate, glutamate, malate, α-ketoglutarate, aspartate, citrate and succinate, some of which may be neuron or astrocyte specific. GLAST, GLT1 and GLUT1 are localized in astrocytes. EEAC1 and GLUT3 are localized to neurons. Annotations as in Fig. 1 [67, 73, 75, 85, 87, 104–107, 120, 133, 142, 143, 145, 163, 253, 254]. Note: Bold indicates an enzyme expression or activity has been assayed. Bold black or red indicates upregulation. Bold grey or blue indicates downregulation. Bolding of an enzyme or metabolite name indicate protein expression or concentration alterations. Partial bolding or coloring indicates differential expression changes among subunits. Bolding and/or coloring of arrows indicate activity changes. No change is indicated by a brown script font or a half open brown arrowhead. The default sans serif black font and thin black arrows with small heads indicate that no specific information is available. Combinations of symbol changes and asterisks (*) indicate conflicting reports from different laboratories.