Retrophosphorylation of Mkk1 and Mkk2 MAPKKs by the Slt2 MAPK in the Yeast Cell Integrity Pathway

Jiménez-Sánchez, María; Cid, Víctor J.; Molina, Marı́a

doi:10.1074/jbc.m706270200

Cited by 40 publications

(36 citation statements)

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“…Mkk1 and Mkk2 are subject to retrophosphorylation by Mpk1, which appears to be a negative feedback regulatory mechanism and requires a D motif in the MEKs (Jimenez-Sanchez et al 2007).…”

Section: Pkc1 and The Cwi Mapk Cascadementioning

confidence: 99%

Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

2011

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The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to the Rho1 GTPase, which mobilizes a physiologic response through a variety of effectors. Activation of CWI signaling regulates the production of various carbohydrate polymers of the cell wall, as well as their polarized delivery to the site of cell wall remodeling. This review article centers on CWI signaling in Saccharomyces cerevisiae through the cell cycle and in response to cell wall stress. The interface of this signaling pathway with other pathways that contribute to the maintenance of cell wall integrity is also discussed.

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“…Mkk1 and Mkk2 are subject to retrophosphorylation by Mpk1, which appears to be a negative feedback regulatory mechanism and requires a D motif in the MEKs (Jimenez-Sanchez et al 2007).…”

Section: Pkc1 and The Cwi Mapk Cascadementioning

confidence: 99%

Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

2011

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“…Recombinant Mkk1 bound to the beads was phosphorylated in vitro with 32 P-labeled ATP using a yeast extract from a strain overexpressing the hyperactive Bck1-20 allele as a source of kinase activity to increase the amount of phosphorylated Mkk1. This strain also lacks Slt2 to avoid the retrophosphorylation of Mkk1 exerted by this MAPK in residues different from the conserved activation sites phosphorylated by Bck1 (Jimenez-Sanchez et al 2007). Phosphorylated GST-Mkk1 was then incubated with either recombinant Ptc1, the same amount of heat-inactivated Ptc1, or Ppz1, a PP1-like Ser/ Thr protein phosphatase that has been genetically related to (Lee et al 1993;Posas et al 1993) but is not directly involved in the CWI pathway (Merchan et al 2004).…”

Section: Ptc1 Dephosphorylates In Vitro Gst-mkk1mentioning

confidence: 99%

“…This plasmid was constructed by amplification of the PTC1 ORF with oligonucleotides PTC1_pGEX-Fw and PTC1_pGEX_Rv, digestion of the amplification fragment with SalI and BamHI, and cloning into the same sites of plasmid pGEX-6P1. Bacterial expression of GSTMkk1 was accomplished using plasmid pGEX(KG)-MKK1, as described in Jimenez-Sanchez et al (2007). …”

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confidence: 99%

Wide-Ranging Effects of the Yeast Ptc1 Protein Phosphatase Acting Through the MAPK Kinase Mkk1

et al. 2015

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The Saccharomyces cerevisiae type 2C protein phosphatase Ptc1 is required for a wide variety of cellular functions, although only a few cellular targets have been identified. A genetic screen in search of mutations in protein kinase-encoding genes able to suppress multiple phenotypic traits caused by the ptc1 deletion yielded a single gene, MKK1, coding for a MAPK kinase (MAPKK) known to activate the cell-wall integrity (CWI) Slt2 MAPK. In contrast, mutation of the MKK1 paralog, MKK2, had a less significant effect. Deletion of MKK1 abolished the increased phosphorylation of Slt2 induced by the absence of Ptc1 both under basal and CWI pathway stimulatory conditions. We demonstrate that Ptc1 acts at the level of the MAPKKs of the CWI pathway, but only the Mkk1 kinase activity is essential for ptc1 mutants to display high Slt2 activation. We also show that Ptc1 is able to dephosphorylate Mkk1 in vitro. Our results reveal the preeminent role of Mkk1 in signaling through the CWI pathway and strongly suggest that hyperactivation of Slt2 caused by upregulation of Mkk1 is at the basis of most of the phenotypic defects associated with lack of Ptc1 function.KEYWORDS synthetic genetic interactions; cell-wall integrity pathway; protein dephosphorylation; Saccharomyces cerevisiae P ROTEIN kinases play an essential role in nearly every aspect of cell physiology, and the activity of these key players is frequently modulated by phosphorylation. Therefore, protein phosphatases (PPases) are important regulators of protein kinases and cellular homeostasis. Among them, type 2C Ser/Thr PPases constitute an evolutionarily conserved group that, in contrast to other PPase families, are monomeric enzymes apparently lacking regulatory subunits. In the yeast Saccharomyces cerevisiae, seven members (Ptc1-Ptc7) have been identified and at least partially characterized [see Arino et al. (2011) for a review].Ptc1 is the closest homolog of human Wip1, a phosphatase involved in the regulation of stress-induced and DNA damage-induced networks in diverse physiologic and pathologic conditions (Le Guezennec and Bulavin 2010;Zhu and Bulavin 2012) and by far the most widely studied yeast isoform. Both the large number of characteristic phenotypes and the specific changes in the transcriptomic profile (Gonzalez et al. 2006) derived from deletion of the gene suggest that this phosphatase is involved in a large variety of cellular processes not shared by other Ptc family members. Early evidence indicated that Ptc1 was involved in the negative regulation of the high-osmolarity glycerol (HOG) pathway (Maeda et al. 1993;Maeda et al. 1994), and subsequent work demonstrated that Ptc1 could dephosphorylate the Hog1 MAPK in vitro and in vivo (Warmka et al. 2001 interacts with the N-terminal domain of Nbp2, an SH3 domaincontaining protein that serves as an adaptor for the recruitment of Ptc1 to the Pbs2-Hog1 complex, and this interaction is necessary for Ptc1 to participate in the regulation of HOGmediated signaling (Uetz et al. 2000;Ito et al. 2001;Ma...

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“…Interestingly, serine phosphorylation appeared to be slightly enhanced in the inactive forms of Mpk1, suggesting the possibility of negativefeedback regulation of this phosphorylation by Mpk1 activity. Along similar lines, Mpk1 is known to phosphorylate its other regulators, Msg5 and Mkk2 (16,20).…”

Section: Kim Unpublished Results)mentioning

confidence: 90%

Mechanism of Mpk1 Mitogen-Activated Protein Kinase Binding to the Swi4 Transcription Factor and Its Regulation by a Novel Caffeine-Induced Phosphorylation

Truman

Kim

Levin

2009

Molecular and Cellular Biology

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The Mpk1 mitogen-activated protein kinase (MAPK) of the cell wall integrity signaling pathway uses a noncatalytic mechanism to activate the SBF (Swi4/Swi6) transcription factor. Active Mpk1 forms a complex with Swi4, the DNA-binding subunit of SBF, conferring the ability to bind DNA. Because SBF activation is independent of Mpk1 catalytic activity but requires Mpk1 to be in an active conformation, we sought to understand how Mpk1 interacts with Swi4. Mutational analysis revealed that binding and activation of Swi4 by Mpk1 requires an intact D-motif-binding site, a docking surface common to MAPKs that resides distal to the phosphorylation loop but does not require the substrate-binding site, revealing a novel mechanism for MAPK target regulation. Additionally, we found that Mpk1 binds near the autoinhibitory C terminus of Swi4, suggesting an activation mechanism in which Mpk1 substitutes for Swi6 in promoting Swi4 DNA binding. Finally, we show that caffeine is an atypical activator of cell wall integrity signaling, because it induces phosphorylation of the Mpk1 C-terminal extension at Ser423 and Ser428. These phosphorylations were dependent on the DNA damage checkpoint kinases, Mec1/Tel1 and Rad53. Phosphorylation of Ser423 specifically blocked SBF activation by preventing Mpk1 association with Swi4, revealing a novel mechanism for regulating MAPK target specificity.

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Retrophosphorylation of Mkk1 and Mkk2 MAPKKs by the Slt2 MAPK in the Yeast Cell Integrity Pathway

Cited by 40 publications

References 56 publications

Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

Wide-Ranging Effects of the Yeast Ptc1 Protein Phosphatase Acting Through the MAPK Kinase Mkk1

Mechanism of Mpk1 Mitogen-Activated Protein Kinase Binding to the Swi4 Transcription Factor and Its Regulation by a Novel Caffeine-Induced Phosphorylation

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