Publications

• The sedoheptulose kinase CARKL directs macrophage polarization through control of glucose metabolism.

  Haschemi A., Kosma P., Gille L., Evans C.R., Burant C.F., Starkl P., Knapp B., Haas R., Schmid J.A., Jandl C., Amir S., Lubec G., Park J., Esterbauer H., Bilban M., Brizuela L., Pospisilik J.A., Otterbein L.E., Wagner O.

  Immune cells are somewhat unique in that activation responses can alter quantitative phenotypes upwards of 100,000-fold. To date little is known about the metabolic adaptations necessary to mount such dramatic phenotypic shifts. Screening for novel regulators of macrophage activation, we found non ... >> More

  Immune cells are somewhat unique in that activation responses can alter quantitative phenotypes upwards of 100,000-fold. To date little is known about the metabolic adaptations necessary to mount such dramatic phenotypic shifts. Screening for novel regulators of macrophage activation, we found nonprotein kinases of glucose metabolism among the most enriched classes of candidate immune modulators. We find that one of these, the carbohydrate kinase-like protein CARKL, is rapidly downregulated in vitro and in vivo upon LPS stimulation in both mice and humans. Interestingly, CARKL catalyzes an orphan reaction in the pentose phosphate pathway, refocusing cellular metabolism to a high-redox state upon physiological or artificial downregulation. We find that CARKL-dependent metabolic reprogramming is required for proper M1- and M2-like macrophage polarization and uncover a rate-limiting requirement for appropriate glucose flux in macrophage polarization. << Less

  Cell Metab. 15:813-826(2012) [PubMed] [EuropePMC]

• Sedoheptulokinase deficiency due to a 57-kb deletion in cystinosis patients causes urinary accumulation of sedoheptulose: elucidation of the CARKL gene.

  Wamelink M.M., Struys E.A., Jansen E.E., Levtchenko E.N., Zijlstra F.S., Engelke U., Blom H.J., Jakobs C., Wevers R.A.

  The most common mutation in the nephropathic cystinosis (CTNS) gene is a homozygous 57-kb deletion that also includes an adjacent gene carbohydrate kinase-like (CARKL). The latter gene encodes a protein that is predicted to function as a carbohydrate kinase. Cystinosis patients with the common 57- ... >> More

  The most common mutation in the nephropathic cystinosis (CTNS) gene is a homozygous 57-kb deletion that also includes an adjacent gene carbohydrate kinase-like (CARKL). The latter gene encodes a protein that is predicted to function as a carbohydrate kinase. Cystinosis patients with the common 57-kb deletion had strongly elevated urinary concentrations of sedoheptulose (28-451 mmol/mol creatinine; controls and other cystinosis patients <9) and erythritol (234-1110 mmol/mol creatinine; controls and other cystinosis patients <148). Enzyme studies performed on fibroblast homogenates derived from patients carrying the 57-kb deletion revealed 80% reduction in their sedoheptulose phosphorylating activity compared to cystinosis patients with other mutations and controls. This indicates that the CARKL-encoded protein, sedoheptulokinase (SHK), is responsible for the reaction: sedoheptulose + ATP --> sedoheptulose-7-phosphate + ADP and that deletion of CARKL causes urinary accumulation of sedoheptulose and erythritol. << Less

  Hum. Mutat. 29:532-536(2008) [PubMed] [EuropePMC]