Munc18c provides stimulus-selective regulation of GLUT4 but not fatty acid transporter trafficking in skeletal muscle.
Insulin-, and contraction-induced GLUT4 and fatty acid (FA) transporter translocation may share common trafficking mechanisms. Our objective was to examine the effects of partial Munc18c ablation on muscle glucose and FA transport, FA oxidation, GLUT4 and FA transporter (FAT/CD36, FABPpm, FATP1, FATP4) trafficking to the sarcolemma, and FAT/CD36 to mitochondria. In Munc18c(-/+) mice, insulin-stimulated glucose transport and GLUT4 sarcolemmal appearance were impaired, but were unaffected by contraction. Insulin- and contraction-stimulated FA transport, sarcolemmal FA transporter appearance, and contraction-mediated mitochondrial FAT/CD36 were increased normally in Munc18c(-/+) mice. Hence, Munc18c provides stimulus-specific regulation of GLUT4 trafficking, but not FA transporter trafficking.
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Swati S
SS
Jain
Laelie A
LA
Snook
Jan F C
JF
Glatz
Joost J F P
JJ
Luiken
Graham P
GP
Holloway
Debbie C
DC
Thurmond
Arend
A
Bonen
D000818:Animals; D001692:Biological Transport; D018955:CD36 Antigens / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D006579:Heterozygote; D007328:Insulin / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism; D051938:Munc18 Proteins / Q000378:metabolism*; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D010168:Palmitates / Q000378:metabolism; D012508:Sarcolemma / Q000378:metabolism
D018955:CD36 Antigens; D005227:Fatty Acids; D051275:Glucose Transporter Type 4; D007328:Insulin; D051938:Munc18 Proteins; D010168:Palmitates; C495693:Slc2a4 protein, mouse; C497938:Stxbp1 protein, mouse; D005947:Glucose; D010100:Oxygen