Faculty Profiles - HISAMOTO, Naoki

Papers - HISAMOTO, Naoki

Division display 41 - 60 of about 75 ／ All the affair displays >>

Regulation of Anoxic Death in Caenorhabditis elegans by Mammalian Apoptosis Signal-Regulating Kinase (ASK) Family Proteins. Reviewed

Hayakawa T, Kato K, Hayakawa R, Hisamoto N, Matsumoto K, Takeda K, Ichijo H.

Genetics Vol. 187 ( 3 ) page： 785-792 2011.3

The C. elegans JIP3 protein UNC-16 functions as an adaptor to link kinesin-1 with cytoplasmic dynein. Reviewed

Arimoto M, Koushika SP, Choudhary B, Li C, Matsumoto K, Hisamoto N.

Journal of Neuroscience Vol. 31 page： 2216-2224 2011.2

The ERK-MAPK pathway regulates longevity through SKN-1 and insulin-like signaling in Caenorhabditis elegans. Reviewed

Okuyama T, Inoue H, Ookuma S, Satoh T, Kano K, Honjoh S, Hisamoto N, Matsumoto K, Nishida E.

Journal of Biological Chemistry Vol. 285 ( 39 ) page： 30274-30281 2010.9

Language：English Publishing type：Research paper (scientific journal)

It has not been determined yet whether the ERK-MAPK pathway regulates longevity of metazoans. Here, we show that the Caenorhabditis elegans ERK cascade promotes longevity through the two longevity-promoting transcription factors, SKN-1 and DAF-16. We find that RNAi of three genes, which constitute the ERK cascade (lin-45/RAF1, mek-2/MEK1/2, and mpk-1/ERK1/2), results in reduction of life span. Moreover, RNAi of lip-1, the gene encoding a MAPK phosphatase that inactivates MPK-1, increases life span. Epistasis analyses show that the ERK (MPK-1) cascade-mediated life span extension requires SKN-1, whose function is mediated, at least partly, through DAF-2/DAF-16 insulin-like signaling. MPK-1 phosphorylates SKN-1 on the key sites that are required for SKN-1 nuclear accumulation. Our results also show that one mechanism by which SKN-1 regulates insulin-like signaling is through the regulation of expression of insulin-like peptides. Our findings thus identify a novel ERK-MAPK-mediated signaling pathway that promotes longevity.

Phosphorylation of the conserved transcription factor ATF-7 by PMK-1 p38 MAPK regulates innate immunity in Caenorhabditis elegans. Reviewed

Shivers RP, Pagano DJ, Kooistra T, Richardson CE, Reddy KC, Whitney JK, Kamanzi O, Matsumoto K, Hisamoto N, Kim DH

PLoS Genetics Vol. 6 ( 4 ) page： e1000892 2010.4

Language：English Publishing type：Research paper (scientific journal)

Innate immunity in Caenorhabditis elegans requires a conserved PMK-1 p38 mitogen-activated protein kinase (MAPK) pathway that regulates the basal and pathogen-induced expression of immune effectors. The mechanisms by which PMK-1 p38 MAPK regulates the transcriptional activation of the C. elegans immune response have not been identified. Furthermore, in mammalian systems the genetic analysis of physiological targets of p38 MAPK in immunity has been limited. Here, we show that C. elegans ATF-7, a member of the conserved cyclic AMP-responsive element binding (CREB)/activating transcription factor (ATF) family of basic-region leucine zipper (bZIP) transcription factors and an ortholog of mammalian ATF2/ATF7, has a pivotal role in the regulation of PMK-1-mediated innate immunity. Genetic analysis of loss-of-function alleles and a gain-of-function allele of atf-7, combined with expression analysis of PMK-1-regulated genes and biochemical characterization of the interaction between ATF-7 and PMK-1, suggest that ATF-7 functions as a repressor of PMK-1-regulated genes that undergoes a switch to an activator upon phosphorylation by PMK-1. Whereas loss-of-function mutations in atf-7 can restore basal expression of PMK-1-regulated genes observed in the pmk-1 null mutant, the induction of PMK-1-regulated genes by pathogenic Pseudomonas aeruginosa PA14 is abrogated. The switching modes of ATF-7 activity, from repressor to activator in response to activated PMK-1 p38 MAPK, are reminiscent of the mechanism of regulation mediated by the corresponding ancestral Sko1p and Hog1p proteins in the yeast response to osmotic stress. Our data point to the regulation of the ATF2/ATF7/CREB5 family of transcriptional regulators by p38 MAPK as an ancient conserved mechanism for the control of innate immunity in metazoans, and suggest that ATF2/ATF7 may function in a similar manner in the regulation of mammalian innate immunity.

The Caenorhabditis elegans Ste20-related kinase and Rac-type small GTPaseregulate the JNK signaling pathway mediating the stress response. Reviewed

Fujiki K, Mizuno T, Hisamoto N, Matsumoto K.

Molecular and Cellular Biology Vol. 30 ( 4 ) page： 995-1003 2010.2

Language：English Publishing type：Research paper (scientific journal)

Mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli and a wide variety of environmental stresses. In Caenorhabditis elegans, the stress response is controlled by a JNK-like MAPK signaling pathway, which is regulated by MLK-1 MAPKKK, MEK-1 MAPKK and KGB-1 JNK-like MAPK. In this study, we identify the max-2 gene encoding a C. elegans Ste20-related protein kinase as a component functioning upstream of the MLK-1-MEK-1-KGB-1 pathway. The max-2 loss-of-function mutation is defective in activation of KGB-1, resulting in hypersensitivity to heavy metals. Biochemical analysis reveals that MAX-2 activates MLK-1 through direct phosphorylation of a specific residue in the activation loop of the MLK-1 kinase domain. Our genetic data presented here also show that MIG-2 small GTPase functions upstream of MAX-2 in the KGB-1 pathway. These results suggest that MAX-2 and MIG-2 play a crucial role in mediating the heavy metal stress response regulated by the KGB-1 pathway.

The germinal center kinase GCK-1 Is a negative regulator of MAP kinase activation and apoptosis in the C. elegans germline. Reviewed

Schouest KR, Kurasawa Y, Furuta T, Hisamoto N, Matsumoto K, Schumacher JM.

PLos One Vol. 4 ( 10 ) page： e7450 2009.10

Language：English Publishing type：Research paper (scientific journal)

The germinal center kinases (GCK) constitute a large, highly conserved family of proteins that has been implicated in a wide variety of cellular processes including cell growth and proliferation, polarity, migration, and stress responses. Although diverse, these functions have been attributed to an evolutionarily conserved role for GCKs in the activation of ERK, JNK, and p38 MAP kinase pathways. In addition, multiple GCKs from different species promote apoptotic cell death. In contrast to these paradigms, we found that a C. elegans GCK, GCK-1, functions to inhibit MAP kinase activation and apoptosis in the C. elegans germline. In the absence of GCK-1, a specific MAP kinase isoform is ectopically activated and oocytes undergo abnormal development. Moreover, GCK-1- deficient animals display a significant increase in germ cell death. Our results suggest that individual germinal center kinases act in mechanistically distinct ways and that these functions are likely to depend on organ- and developmental-specific contexts.

Caenorhabditis elegans FOS-1 and JUN-1 regulate plc-1 expression in the spermatheca to control ovulation. Reviewed

Hiatt SM, Duren HM, Shyu YJ, Ellis RE, Hisamoto N, Matsumoto K, Kariya K, Kerppola TK, Hu CD.

Molecular Biology of the Cell Vol. 20 ( 17 ) page： 3888-95 2009.9

Language：English Publishing type：Research paper (scientific journal)

Fos and Jun are components of activator protein-1 (AP-1) and play crucial roles in the regulation of many cellular, developmental, and physiological processes. Caenorhabditis elegans fos-1 has been shown to act in uterine and vulval development. Here, we provide evidence that C. elegans fos-1 and jun-1 control ovulation, a tightly regulated rhythmic program in animals. Knockdown of fos-1 or jun-1 blocks dilation of the distal spermathecal valve, a critical step for the entry of mature oocytes into the spermatheca for fertilization. Furthermore, fos-1 and jun-1 regulate the spermathecal-specific expression of plc-1, a gene that encodes a phospholipase C (PLC) isozyme that is rate-limiting for inositol triphosphate production and ovulation, and overexpression of PLC-1 rescues the ovulation defect in fos-1(RNAi) worms. Unlike fos-1, regulation of ovulation by jun-1 requires genetic interactions with eri-1 and lin-15B, which are involved in the RNA interference pathway and chromatin remodeling, respectively. At least two isoforms of jun-1 are coexpressed with fos-1b in the spermatheca, and different AP-1 dimers formed between these isoforms have distinct effects on the activation of a reporter gene. These findings uncover a novel role for FOS-1 and JUN-1 in the reproductive system and establish C. elegans as a model for studying AP-1 dimerization.

LRRK2 modulates vulnerability to mitochondrial dysfunction in Caenorhabditis elegans. Reviewed

Saha S, Guillily MD, Ferree A, Lanceta J, Chan D, Ghosh J, Hsu CH, Segal L, Raghavan K, Matsumoto K, Hisamoto N, Kuwahara T, Iwatsubo T, Moore L, Goldstein L, Cookson M, Wolozin B.

Journal of Neuroscience Vol. 29 ( 29 ) page： 9210-8 2009.7

Language：English Publishing type：Research paper (scientific journal)

Mutations in leucine-rich repeat kinase 2 (LRRK2) cause autosomal-dominant familial Parkinson's disease. We generated lines of Caenorhabditis elegans expressing neuronally directed human LRRK2. Expressing human LRRK2 increased nematode survival in response to rotenone or paraquat, which are agents that cause mitochondrial dysfunction. Protection by G2019S, R1441C, or kinase-dead LRRK2 was less than protection by wild-type LRRK2. Knockdown of lrk-1, the endogenous ortholog of LRRK2 in C. elegans, reduced survival associated with mitochondrial dysfunction. C. elegans expressing LRRK2 showed rapid loss of dopaminergic markers (DAT::GFP fluorescence and dopamine levels) beginning in early adulthood. Loss of dopaminergic markers was greater for the G2019S LRRK2 line than for the wild-type line. Rotenone treatment induced a larger loss of dopamine markers in C. elegans expressing G2019S LRRK2 than in C. elegans expressing wild-type LRRK2; however, loss of dopaminergic markers in the G2019S LRRK2 nematode lines was not statistically different from that in the control line. These data suggest that LRRK2 plays an important role in modulating the response to mitochondrial inhibition and raises the possibility that mutations in LRRK2 selectively enhance the vulnerability of dopaminergic neurons to a stressor associated with Parkinson's disease.

*C. elegans WNK-STE20 pathway regulates tube formation by modulating ClC channel activity Reviewed

Naoki Hisamoto, Tetsuo Moriguchi, Seiichi Urushiyama, Shohei Mitani, Hiroshi Shibuya, Kunihiro Matsumoto

EMBO reports Vol. 9 page： 70-75 2008

Language：English Publishing type：Research paper (scientific journal)

WNK kinases comprise a small group of unique serine/threonine protein kinases conserved among multicellular organisms. Mutations in WNK1/4 cause pseudohypoaldosteronism type II, a form of hypertension. WNKs have been linked to the STE20 kinases and ion carriers, but the underlying molecular mechanisms by which WNKs regulate cellular processes in whole animals are unknown. The C. elegans WNK-like kinase WNK-1 interacts with and phosphorylates GCK-3, a STE20-like kinase that is known to inactivate CLH-3, a CIC chloride channel. The wnk-1 or gck-3 deletion mutation causes an Exc phenotype, a defect in the tubular extension of excretory canals. Expression of the activated form of GCK-3 or the clh-3 deletion mutation can partially suppress wnk-1 or gck-3 defects, respectively. These results suggest that WNK-1 controls the tubular formation of excretory canals by activating GCK-3, resulting in downregulation of CIC channel activity.

Role of the C. elegans Shc adaptor protein in the JNK signaling pathway. Reviewed

Mizuno T, Fujiki K, Sasakawa A, Hisamoto N, Matsumoto K.

Molecular and Cellular Biology Vol. in press 2008

*LRK-1, a C. elegans PARK8-related kinase, regulates axonal-dendritic polarity of SV proteins Reviewed

Sakaguchi-Nakashima A, Meir JY, Jin Y, Matsumoto K, Hisamoto N.

Current biology Vol. 17 ( 7 ) page： 592-598 2007.4

Language：English Publishing type：Research paper (scientific journal)

Neurons are polarized cells that contain distinct sets of proteins in their axons and dendrites. Synaptic vesicles (SV) and many SV proteins are exclusively localized in the presynaptic regions but not in dendrites. Despite their fundamental importance, the mechanisms underlying the polarized localization of SV proteins remain unclear. The transparent nematode Caenorhabditis elegans can be used to examine sorting and transport of SV proteins in vivo. Here, we identify a novel protein kinase LRK-1, a C. elegans homolog of the familial Parkinsonism gene PARK8/LRRK2 that is required for polarized localization of SV proteins. In lrk-1 deletion mutants, SV proteins are localized to both presynaptic and dendritic endings in neurons. This aberrant localization of SV proteins in the dendrites is dependent on the AP-1 mu1 clathrin adaptor UNC-101, which is involved in polarized dendritic transport, but not on UNC-104 kinesin, which is required for the transport of SV to presynaptic regions. The LRK-1 proteins are localized in the Golgi apparatus. These results suggest that the LRK-1 protein kinase determines polarized sorting of SV proteins to the axons by excluding SV proteins from the dendrite-specific transport machinery in the Golgi.

?WNK1 regulates phosphorylation of cation-chloride-coupled cotransporters via the STE20-related kinases, SPAK and OSR1. Reviewed

Moriguchi T, Urushiyama S, Hisamoto N, Iemura S, Uchida S, Natsume T, Matsumoto K, Shibuya H.

Journal of Biological Chemistry Vol. 280 ( 52 ) page： 42685-42693 2005.12

Language：English Publishing type：Research paper (scientific journal)

The WNK1 and WNK4 genes have been found to be mutated in some patients with hyperkalemia and hypertension caused by pseudohypoaldosteronism type II. The clue to the pathophysiology of pseudohypoaldosteronism type II was its striking therapeutic response to thiazide diuretics, which are known to block the sodium chloride cotransporter (NCC). Although this suggests a role for WNK1 in hypertension, the precise molecular mechanisms are largely unknown. Here we have shown that WNK1 phosphorylates and regulates the STE20-related kinases, Ste20-related proline-alanine-rich kinase (SPAK) and oxidative stress response 1 (OSR1). WNK1 was observed to phosphorylate the evolutionary conserved serine residue located outside the kinase domains of SPAK and OSR1, and mutation of the OSR1 serine residue caused enhanced OSR1 kinase activity. In addition, hypotonic stress was shown to activate SPAK and OSR1 and induce phosphorylation of the conserved OSR1 serine residue, suggesting that WNK1 may be an activator of the SPAK and OSR1 kinases. Moreover, SPAK and OSR1 were found to directly phosphorylate the N-terminal regulatory regions of cation-chloride-coupled cotransporters including NKCC1, NKCC2, and NCC. Phosphorylation of NCC was induced by hypotonic stress in cells. These results suggested that WNK1 and SPAK/OSR1 mediate the hypotonic stress signaling pathway to the transporters and may provide insights into the mechanisms by which WNK1 regulates ion balance.

Regulation of the Caenorhabditis elegans oxidative stress defense protein SKN-1 by glycogen synthase kinase-3. Reviewed

An JH, Vranas K, Lucke M, Inoue H, Hisamoto N, Matsumoto K, Blackwell TK.

Proceedings of the National Academy of Sciences of the United States of America Vol. 102 ( 45 ) page： 16275-16280 2005.11

Language：English Publishing type：Research paper (scientific journal)

Oxidative stress plays a central role in many human diseases and in aging. In Caenorhabditis elegans the SKN-1 protein induces phase II detoxification gene transcription, a conserved oxidative stress response, and is required for oxidative stress resistance and longevity. Oxidative stress induces SKN-1 to accumulate in intestinal nuclei, depending on p38 mitogen-activated protein kinase signaling. Here we show that, in the absence of stress, phosphorylation by glycogen synthase kinase-3 (GSK-3) prevents SKN-1 from accumulating in nuclei and functioning constitutively in the intestine. GSK-3 sites are conserved in mammalian SKN-1 orthologs, indicating that this level of regulation may be conserved. If inhibition by GSK-3 is blocked, background levels of p38 signaling are still required for SKN-1 function. WT and constitutively nuclear SKN-1 comparably rescue the skn-1 oxidative stress sensitivity, suggesting that an inducible phase II response may provide optimal stress protection. We conclude that (i) GSK-3 inhibits SKN-1 activity in the intestine, (ii) the phase II response integrates multiple regulatory signals, and (iii), by inhibiting this response, GSK-3 may influence redox conditions.

?The C. elegans p38 MAPK pathway regulates nuclear localization of the transcription factor SKN-1 in oxidative stress response. Reviewed

Inoue H, Hisamoto N, An JH, Oliveira RP, Nishida E, Blackwell TK, Matsumoto K.

Genes and Development Vol. 19 ( 19 ) page： 2278-2283 2005.10

Language：English Publishing type：Research paper (scientific journal)

The evolutionarily conserved p38 mitogen-activated protein kinase (MAPK) cascade is an integral part of the response to a variety of environmental stresses. Here we show that the Caenorhabditis elegans PMK-1 p38 MAPK pathway regulates the oxidative stress response via the CNC transcription factor SKN-1. In response to oxidative stress, PMK-1 phosphorylates SKN-1, leading to its accumulation in intestine nuclei, where SKN-1 activates transcription of gcs-1, a phase II detoxification enzyme gene. These results delineate the C. elegans p38 MAPK signaling pathway leading to the nucleus that responds to oxidative stress.

The Caenorhabditis elegans UNC-14 RUN domain protein binds to the kinesin-1 and UNC-16 complex and regulates synaptic vesicle localization. Reviewed

Sakamoto R, Byrd DT, Brown HM, Hisamoto N, Matsumoto K, Jin Y.

Molecular Biology of the Cell Vol. 16 ( 2 ) page： 483-496 2005.2

Language：English Publishing type：Research paper (scientific journal)

Kinesin-1 is a heterotetramer composed of kinesin heavy chain (KHC) and kinesin light chain (KLC). The Caenorhabditis elegans genome has a single KHC, encoded by the unc-116 gene, and two KLCs, encoded by the klc-1 and klc-2 genes. We show here that UNC-116/KHC and KLC-2 form a complex orthologous to conventional kinesin-1. KLC-2 also binds UNC-16, the C. elegans JIP3/JSAP1 JNK-signaling scaffold protein, and the UNC-14 RUN domain protein. The localization of UNC-16 and UNC-14 depends on kinesin-1 (UNC-116 and KLC-2). Furthermore, mutations in unc-16, klc-2, unc-116, and unc-14 all alter the localization of cargos containing synaptic vesicle markers. Double mutant analysis is consistent with these four genes functioning in the same pathway. Our data support a model whereby UNC-16 and UNC-14 function together as kinesin-1 cargos and regulators for the transport or localization of synaptic vesicle components.

Integration of Caenorhabditis elegans MAPK pathways mediating immunity and stress resistance by MEK-1 MAPK kinase and VHP-1 MAPK phosphatase. Reviewed

Kim DH, Liberati NT, Mizuno T, Inoue H, Hisamoto N, Matsumoto K, Ausubel FM.

Proceedings of the National Academy of Sciences of the United States of America Vol. 101 ( 30 ) page： 10990-10994 2004.7

Language：English Publishing type：Research paper (scientific journal)

The p38 and JNK classes of mitogen-activated protein kinases (MAPKs) have evolutionarily conserved roles in the control of cellular responses to microbial and abiotic stresses. The mechanisms by which crosstalk between distinct p38 and c-Jun N-terminal kinase (JNK) MAPK pathways occurs with resultant integration of signaling information have been difficult to establish, particularly in the context of whole organism physiology. In Caenorhabditis elegans a PMK-1 p38 MAPK pathway is required for resistance to bacterial infection, and a KGB-1 JNK-like MAPK pathway has recently been shown to mediate resistance to heavy metal stress. Here, we show that two components of the KGB-1 pathway, MEK-1 MAPK kinase (MAPKK), a homolog of mammalian MKK7, and VHP-1 MAPK phosphatase (MKP), a homolog of mammalian MKP7, also regulate pathogen resistance through the modulation of PMK-1 activity. The regulation of p38 and JNK-like MAPK pathways mediating immunity and heavy metal stress by common MAPKK and MKP signaling components suggests pivotal roles for MEK-1 and VHP-1 in the integration of diverse stress signals contributing to pathogen resistance in C. elegans. In addition, these data point to mechanisms in multicellular organisms by which signals transduced by distinct MAPK pathways may be subject to physiological integration at the level of regulation of MAPK activity by MAPKKs and MKPs.

Roles of MAP kinase cascades in Caenorhabditis elegans. Invited

Sakaguchi A, Matsumoto K, Hisamoto N.

Journal of Biochemistry (Tokyo) Vol. 136 ( 1 ) page： 7-11 2004.7

Authorship：Lead author Language：English

Mitogen-activated protein kinases (MAPKs) are serine/threonine protein kinases that are activated by diverse stimuli such as growth factors, cytokines, neurotransmitters and various cellular stresses. MAPK cascades are generally present as three-component modules, consisting of MAPKKK, MAPKK and MAPK. The precise molecular mechanisms by which these MAPK cascades transmit signals is an area of intense research, and our evolving understanding of these signal cascades has been facilitated in great part by genetic analyses in model organisms. One organism that has been commonly used for genetic manipulation and physiological characterization is the nematode Caenorhabditis elegans. Genes sequenced in the C. elegans genome project have furthered the identification of components involved in several MAPK pathways. Genetic and biochemical studies on these components have shed light on the physiological roles of MAPK cascades in the control of cell fate decision, neuronal function and immunity in C. elegans.

The Caenorhabditis elegans MAPK phosphatase VHP-1 mediates a novel JNK-like signaling pathway in stress response. Reviewed

Mizuno T, Hisamoto N, Terada T, Kondo T, Adachi M, Nishida E, Kim DH, Ausubel FM, Matsumoto K.

EMBO Journal Vol. 23 ( 11 ) page： 2226-2234 2004.6

Language：English Publishing type：Research paper (scientific journal)

Mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli and to a wide variety of environmental stresses. MAPK cascades can be inactivated at the MAPK activation step by members of the MAPK phosphatase (MKP) family. However, the components that act in MKP-regulated pathways have not been well characterized in the context of whole organisms. Here we characterize the Caenorhabditis elegans vhp-1 gene, encoding an MKP that acts preferentially on the c-Jun N-terminal kinase (JNK) and p38 MAPKs. We found that animals defective in vhp-1 are arrested during larval development. This vhp-1 defect is suppressed by loss-of-function mutations in the kgb-1, mek-1, and mlk-1 genes encoding a JNK-like MAPK, an MKK7-type MAPKK, and an MLK-type MAPKKK, respectively. The genetic and biochemical data presented here demonstrate a critical role for VHP-1 in the KGB-1 pathway. Loss-of-function mutations in each component in the KGB-1 pathway result in hypersensitivity to heavy metals. These results suggest that VHP-1 plays a pivotal role in the integration and fine-tuning of the stress response regulated by the KGB-1 MAPK pathway.

An NDPase links ADAM protease glycosylation with organ morphogenesis in C. elegans. Reviewed

Nishiwaki K, Kubota Y, Chigira Y, Roy SK, Suzuki M, Schvarzstein M, Jigami Y, Hisamoto N, Matsumoto K.

Nature Cell biology Vol. 6 ( 1 ) page： 31-37 2004.1

Language：English Publishing type：Research paper (scientific journal)

In the nematode Caenorhabditis elegans, the gonad acquires two U-shaped arms through the directed migration of its distal tip cells (DTCs), which are located at the tip of the growing gonad arms. A member of the ADAM (a disintegrin and metalloprotease) family, MIG-17, regulates directional migration of DTCs: MIG-17 is synthesized and secreted from the muscle cells of the body wall, and diffuses to the gonad where it is required for DTC migration. The mig-23 mutation causes defective migration of DTCs and interacts genetically with mig-17. Here, we report that mig-23 encodes a membrane-bound nucleoside diphosphatase (NDPase) required for glycosylation and proper localization of MIG-17. Our findings indicate that an NDPase affects organ morphogenesis through glycosylation of the MIG-17 ADAM protease.

SEK-1 MAPKK mediates Ca2+ signaling to determine neuronal asymmetric development in Caenorhabditis elegans. Reviewed

EMBO Reports Vol. 3 ( 1 ) page： 56-62 2002

Language：English Publishing type：Research paper (scientific journal)

The mitogen-activated protein kinase (MAPK) pathway is a highly conserved signaling cascade that converts extracellular signals into various outputs. In Caenorhabditis elegans, asymmetric expression of the candidate odorant receptor STR-2 in either the left or the right of two bilaterally symmetrical olfactory AWC neurons is regulated by axon contact and Ca2+ signaling. We show that the MAPK kinase (MAPKK) SEK-1 is required for asymmetric expression in AWC neurons. Genetic and biochemical analyses reveal that SEK-1 functions in a pathway downstream of UNC-43 and NSY-1, Ca2+/calmodulin-dependent protein kinase II (CaMKII) and MAPK kinase kinase (MAPKKK), respectively. Thus, the NSY-1-SEK-1-MAPK cascade is activated by Ca2+ signaling through CaMKII and establishes asymmetric cell fate decision during neuronal development.

　 PREV - NEXT 　

<HISAMOTO, Naoki>

Papers - HISAMOTO, Naoki