Cloning of an L-3-hydroxyacyl-CoA dehydrogenase that interacts with the GLUT4 C-terminus

Evidence indicates that the carboxy-terminal cytoplasmic domain of glucose transporter 4 (GLUT4) is important for the regulation of GLUT4 in muscle an d adipocytes, We cloned from a human skeletal muscle cDNA library a 34-kDa protein which interacts with GLUT4 C-terminal cytoplasmic domain in a two-h ybrid system and also with GLUT4 C-terminus synthetic peptide in an in vitr o binding assay. This protein, called YP10, showed a high degree (>90%) of sequence homology with L-3-hydroxyacyl-CoA dehydrogenase (HAD) and had a de hydrogenase activity similar to pig heart HAD, which was inhibited by GLUT4 C-terminus synthetic peptide. An antiserum raised against pig heart HAD al so reacted with YP10, Western blot analysis using this antiserum revealed a bundant immunoreactivity only in the mitochondria- and plasma membrane-enri ched fractions of rat adipocytes, Northern blots revealed that YP10 mRNA is most abundant in skeletal and heart muscle, These findings suggest that YP 10, a HAD isoform, interacts with GLUT4 at the plasma membrane and may play a role in cross-talk between glucose transport and fatty acid metabolism. (C) 1999 Academic Press.