Frank Nunes et al. (2006) European Worm Meeting "Evaluating the Role of the Neuronal MAP Kinase JNK-1 in Orientation Behavior and Thermotaxis"

Frank Nunes, Arne Henkel, Melanie Voss, Rudiger J. Paul, Marc Wolf

[European Worm Meeting, 2006]

The C.elegans MAP kinase JNK1 is a homolog of human stress activated protein kinases (SAPK). jnk1 deletion mutants are shortlived and more susceptible to heavy metal stress. On the other hand, If JNK1 was overexpressed, worms showed an increased resistance to oxidative stress and a prolonged lifespan (Oh et al., 2005, Villanueva et al., 2001). As shown by GFP reporter gene assays, JNK-1 is exclusively expressed in the worms nervous system (Kawasaki et al., 1999). By western blot analyses we could demonstrate an increasing activation of JNK-1 with rising but moderate temperatures, which should not be a harmful stress to C. elegans. Therefore we started to investigate the role of JNK-1 in thermotaxis behavior. Indeed jnk-1 deletion mutants [VC8 (gk7)] have an altered temperature preference compared to the wildtype (Bristol N2) when placed on a linear temperature gradient. The wildtype prefers temperatures between 15C and 20C whereas jnk-1 deletion mutants are predominantly found between 15C and 24C, thus having a broader temperature preference range. C. elegans explores its environment by modulating the frequency of occasional turns and reversals. When the environmental conditions are unfavorable reversals or sharp turns and consequently reorientation become more frequent (Gray et al., 2005). We have found that jnk-1-deletion mutants show significantly lower rates of orientation movements at 20C and 25C, which could be the reason for the observed altered temperature preference. Thus it is possible that cellular stress response as well as stress avoidance behavior are both activated in a coordinated manner through JNK-1.

J Grabitzki et al. (2004) European Worm Meeting "THE PCOME OF CAENORHABDITIS ELEGANS IDENTIFICATION OF PHOSPHORYLCHOLINE-SUBSTITUTED PROTEINS AND COMPARISON OF DEVELOPMENTAL CHANGES IN THE EXPRESSION OF THIS EPITOPE"

R Geyer, G Lochnit, J Grabitzki

[European Worm Meeting, 2004]

Caenorhabditis elegans has been found to be good model system for parasitic nematodes, drug screening and developmental studies. Like the respective parasitic worms, C. elegans expresses glycosphingolipids and glycoproteins, carrying, in part, phosphorylcholine (PC) substitutents, which might play important roles in nematode development, fertility and, at least in the case of parasites, the survival within the host (1). With the exception of a major secretory/ excretory product from Achanthocheilonema viteae (ES-62) (2) and the aspartyl-protease ASP-6 (3), no other proteins carrying this epitope has been identified and studied in detail yet. For C. elegans two N-linked PC-epitopes have been reported so far: (I) a pentamannosyl-core structure carrying three PC-residues (4) and (II) a trimannosyl-core species elongated by a N-acetylglucosamine substituted at C-6 with PC (5). Furthermore, in Dauer larvae of C. elegans there was evidence for the presence of glycans with the composition PC1Hex3HexNAc3 to PC2dHex2Hex4HexNAc7 (6). Here we present the 2D-electrophoretic separation of C. elegans proteins, the comparison of the PC-substitution pattern in distinct developmental stages and the mass spectrometric identification of PC-modified proteins. References: 1.Lochnit, G., Dennis, R. D., and Geyer, R. (2000) Biol Chem 381, 839-847 2.Harnett, W., Harnett, M. M., and Byron, O. (2003) Curr Protein Pept Sci 4, 59-71 3.Lochnit, G., Grabitzki, J., Henkel, B., and Geyer, R. (2003) Biochemical Journal submitted 4.Cipollo, J. F., Costello, C. E., and Hirschberg, C. B. (2002) J Biol Chem 277, 49143-49157 5.Haslam, S. M., Gems, D., Morris, H. R., and Dell, A. (2002) Biochem. Soc. Symp. 69, 117-134 6.Cipollo, J. F., Awad, A., Costello, C. E., Robbins, P. W., and Hirschberg, C. B. (2004) Proc Natl Acad Sci U S A 101, 3404-3408