Worm Breeder's Gazette 16(3): 26 (June 1, 2000)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Isolation of components which may be involved in the C. elegans JNK pathways using yeast system

Masato Kawasaki1, Miho Tanaka-Hino1, Naoki Hisamoto1, Kunihiro Matsumoto1,2

1 Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, JAPAN
2 g44177a@nucc.cc.nagoya-u.ac.jp

The c-Jun N-terminal kinase (JNK) of MAP kinase (MAPK) superfamily is activated in response to a variety of cellular stresses and is involved in the apoptosis in neurons. The C. elegans JNK pathway is mediated by JNK-1 (MAPK) and JKK-1 (MAPKK), and functions in type D GABAergic motor neurons to modulate coordinated locomotion (1). To gain more insights into the mechanism of C. elegans JNK pathway, we isolated candidates for components involved the JNK pathway using yeast system.

In yeast, the Ssk2/Ssk22 (MAPKKK)-Hog1 (MAPK)-Pbs2 (MAPKK) pathway regulates osmotic response. To isolate factors which can activate JNK-1 in yeast, we screened C. elegans cDNA library that can rescue pbs2 mutants in a JNK-1 dependent manner. Previously, we have isolated sek-1 and jkk-1, both of which encode MAPKKs in this screening (1, 2). In addition, three different cDNA clones were isolated. One of them is F44D12.4 which encodes a protein carrying a PDZ domain homologous to RGS-GAIP interacting protein. The second clone is F17C8.4 which encodes a Ras-like protein. The third clone is E01G6.2 encoding a novel protein with no homology to known proteins.

To isolate components which can activate C. elegans SEK-1 (MAPKK) in yeast, we screened C. elegans cDNA library that can rescue ssk2 ssk22 pbs2 mutants in the presence of SEK-1 and JNK-1. One cDNA clone was isolated, which is C29F7.1 encoding a novel protein.

To isolate C. elegans genes whose products may affect the yeast Pbs2, we screened C. elegans cDNA library that can rescue ssk2 ssk22 mutants. Two different cDNA clones were isolated. One of them was W09C5.7 encoding a novel protein and the other clone was F33D11.9b encoding a protein carrying a DHHC domain.

We screened for interactors with SEK-1 or JKK-1 using the yeast two-hybrid system. As SEK-1-binding protein, we obtained seb-1 (sek-1 binding protein-1), whose product belongs to synaptotagmin family. SEB-1 also interacted with JNK-1 by two-hybrid system. As JKK-1-binding protein, we isolated one clone which is CO2F5.4 encoding a novel protein.


1. Kawasaki et al., EMBO Journal 18: 3604-3615 (1999)

2. Miho Tanaka et al., Worm Breeder's Gazette 15 (4): 30 (1998)