Project description:We performed a RNA immunoprecipitations experiments using gfp-specific antibodies to precipitate gfp-tagged La proteins from from gfp-La wild type and sumoylation deficient La mutant (K41/200R) cells and found that specific mRNAs are preferentially enriched gfp-La wild type RIPs when compared to sumoylation deficient La mutant (K41/200R) RIPs.
Project description:The term "molecular ZIP (or area) codes" refers to an originally hypothetical system of cell adhesion molecules that would control cell trafficking in the body. Subsequent discovery of the integrins, cadherins, and other cell adhesion molecules confirmed this hypothesis. The recognition system encompassing integrins and their ligands came particularly close to fulfilling the original ZIP code hypothesis, as multiple integrins with closely related specificities mediate cell adhesion by binding to an RGD or related sequence in various extracellular matrix proteins. Diseased tissues have their own molecular addresses that, although not necessarily involved in cell trafficking, can be made use of in targeted drug delivery. This article discusses the molecular basis of ZIP codes and the extensive effort under way to harness them for drug delivery purposes.
Project description:Membrane traffic in eukaryotic cells is mediated by transport vesicles that bud from a precursor compartment and are transported to their destination compartment where they dock and fuse. To reach their intracellular destination, transport vesicles contain targeting signals such as Rab GTPases and polyphosphoinositides that are recognized by tethering factors in the cytoplasm and that connect the vesicles with their respective destination compartment. The final step, membrane fusion, is mediated by SNARE proteins. SNAREs are connected to targeting signals and tethering factors by multiple interactions. However, it is still debated whether SNAREs only function downstream of targeting and tethering or whether they also participate in regulating targeting specificity. Here, we review the evidence and discuss recent data supporting a role of SNARE proteins as targeting signals in vesicle traffic.
Project description:ZIP-3 has been shown to repress the mitochondrial-UPR genes and immune response during P. aeruginosa infection. To identify genes repressed by ZIP-3, we compared transcript profiles from wildtype and zip-3(gk3164) worms raised on P. aeruginosa or E. coli.
Project description:We recently identified lysine L-lactylation (KL-la) on histones that can be labelled by L-lactate, the end-product of glycolysis. KL-la has two structural isomers, namely N--(carboxyethyl) lysine (Kce) and lysine D-lactylation (KD-la), which can also be caused by metabolites associated with glycolysis. It is unknown if perturbations of glycolysis can lead to dysregulation of KD-la and Kce, in addition to KL-la. Further, current methods have a difficulty to distinguish among these isomers in cellular contexts. To investigate these questions, we first generated specific antibodies against each one of these three modifications. These reagents enable us to distinguish these three isomers. We demonstrated that KL-la, but not KD-la and Kce, is dynamically regulated by glycolysis. KD-la and Kce occur mainly when the major glycolytic pathway is blocked downstream or when the glyoxalase system is incomplete. This result was also independently confirmed by orthogonal HPLC-mass spectrometry, showing that KL-la is the predominant isomer of lactylation on cellular histones. Finally, we demonstrated that lactyl-CoA, an intermediate between L-lactate and lactylation, is dynamically regulated by glycolysis and is positively correlated with KL-la. Thus, our study clearly shows that KL-la, but not KD-la and Kce, is the major glycolytic- and the Warburg-effect associated responsive modification in cells.