| Myotubularin-related protein 14 (MTMR14), also known as Jumpy, is a myotubularin-related phosphoinositol-3-phosphate (PI3P) phosphatase. Mutations in the MTMR14 gene have been associated with centronuclear myopathy. MTMR14 deficiency in mice leads to altered calcium homeostasis and muscle disorders. MTMR14 has also been shown to play a role in autophagy, a process that is highly regulated by phosphatidylinositides through the type III PI3K, Vps34. MTMR14 was localized to autophagic isolation membranes and early autophagosomes. In these studies, MTMR14 inhibited autophagy and mutations of MTMR14 associated with centronuclear myopathy were also defective in autophagy inhibition. In zebrafish, MTMR14 knockdown was shown to increase the number of autophagosomes, suggesting that its activity is associated with an inhibition of autophagy. |
