# Mechanisms of selective signaling in MAP kinase phosphorylation networks

> **NIH NIH R01** · YALE UNIVERSITY · 2022 · $351,750

## Abstract

ABSTRACT
Mitogen-activated protein kinase (MAPK) cascades are core components of signaling networks mediating
responses to a diverse array of cellular stimuli in eukaryotes. Despite having high sequence similarity, the major
MAPK families are activated in response to different stimuli and phosphorylate largely unique sets of substrates.
Specificity in MAPK signaling pathways is thought to be conferred by interaction of short linear sequence motifs
in substrates and regulators to regions of the kinase domain separate from the catalytic center. However, docking
sites binding to all families of MAPK conform to common sequence motifs, and it is therefore unclear how
selectively is achieved for an individual MAPK. The goals of our proposed studies are to identify new substrates
and regulators in MAPK signaling networks, to understand how signaling specificity is encoded in the primary
sequence of MAPKs and their interactors, and to reveal how disease-associated mutations change connections
in MAPK signaling networks. In preliminary studies, we developed a yeast-based screening platform to identify
human proteome-derived sequences that interact with MAPKs. Hits from screens of ERK2, p38α and JNK1
docking sequences were highly enriched for known interaction partners and conformed to sequence motifs that
appear to confer MAPK-selective interactions. We will examine the capacity of these sequence motifs to mediate
selective interactions in vitro and in cultured cells. We further propose to investigate putative novel MAPK
substrates identified in our screens, in particular JNK substrates involved in regulation of Rho GTPase signaling.
To understand how the MAPK docking groove encodes specific interactions, we will solve X-ray crystal structures
of different classes of peptides in complex with ERK2 and p38α. Guided by these structures, others previously
reported, and saturation mutagenesis screens, we will identify key determinants that distinguish the docking
grooves of different MAPKs. We will also investigate how reported gain-of-function mutations in ERK MAPKs
change its binding specificity and perturb the network properties of ERK signaling in cells. Finally, we will
investigate why MAPK kinases have such exquisite specificity for their cognate MAPKs despite having non-
selective docking site and catalytic site interactions. Overall these studies will establish new connections in
MAPK pathways and elucidate how those connections are made. This research will provide a more complete
understanding of signaling pathways critical for basic cellular process in normal physiology and in disease.

## Key facts

- **NIH application ID:** 10402942
- **Project number:** 5R01GM135331-03
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** BENJAMIN E TURK
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $351,750
- **Award type:** 5
- **Project period:** 2020-08-15 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10402942

## Citation

> US National Institutes of Health, RePORTER application 10402942, Mechanisms of selective signaling in MAP kinase phosphorylation networks (5R01GM135331-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10402942. Licensed CC0.

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