Related Experiment Video

Updated: Mar 12, 2026

Identification of Transcription Factor Regulators using Medium-Throughput Screening of Arrayed Libraries and a Dual-Luciferase-Based Reporter
11:32

Identification of Transcription Factor Regulators using Medium-Throughput Screening of Arrayed Libraries and a Dual-Luciferase-Based Reporter

Published on: March 27, 2020

7.5K

EYA1's Conformation Specificity in Dephosphorylating Phosphothreonine in Myc and Its Activity on Myc Stabilization in

Jun Li1, Yoel Rodriguez2,3, Chunming Cheng1

  • 1Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA.

Molecular and Cellular Biology
|November 1, 2016
PubMed

Insights

EYA1 dephosphorylates Myc at T58, stabilizing it and promoting breast cancer cell growth. Depleting EYA1 destabilizes Myc, hindering cell cycle progression and revealing a key mechanism in cancer.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Cancer Research

Background:

  • EYA1 is overexpressed in breast cancer, correlating with Myc accumulation and decreased phospho-T58 (pT58) levels.
  • EYA1 acts as a protein phosphatase, dephosphorylating Myc at pT58 to regulate Myc levels.
  • The precise role of EYA1-mediated Myc dephosphorylation in breast cancer and EYA1's substrate specificity remain unclear.

Purpose of the Study:

  • To investigate the critical function of EYA1-mediated Myc dephosphorylation in regulating Myc protein stability in breast cancer.
  • To elucidate the substrate specificity of EYA1.
  • To understand the structural and mechanistic basis of EYA1's phosphatase activity on Myc.

Main Methods:

  • Depletion of EYA1 using short hairpin RNA (shRNA) in breast cancer cells.
  • Analysis of Myc protein stability, pT58 levels, cell doubling time, and cell cycle progression.
  • Investigation of c-Myc binding to FBW7 and c-Myc ubiquitination.
  • Enzymatic assays and nuclear magnetic resonance (NMR) analysis to determine EYA1's phosphatase activity and substrate specificity.

Main Results:

  • EYA1 depletion destabilized Myc, increased pT58 levels, slowed cell doubling, and impaired cell cycle progression.
  • EYA1 stabilized c-Myc by reducing c-Myc-FBW7 binding and ubiquitination.
  • EYA1 possesses dual phosphatase activities (not just tyrosine phosphatase) and interacts with substrates via both N- and C-terminal domains.
  • EYA1 exhibits conformational specificity for phospho-T58 of Myc.

Conclusions:

  • EYA1 dephosphorylation of Myc at T58 is critical for Myc protein stability and breast cancer cell proliferation.
  • EYA1 regulates the FBW7-mediated Myc degradation pathway, offering a novel mechanism for Myc deregulation in cancer.
  • EYA1 has dual phosphatase activities and specific conformational preference for phospho-T58 of Myc, providing structural insights into its function.
Keywords:
EYA1FBW7Mycbreast cancercell proliferationdegradationderegulationthreonine phosphatase

More Related Videos

Yeast As a Chassis for Developing Functional Assays to Study Human P5314:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

10.1K
Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene08:18

Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene

Published on: December 31, 2014

28.9K

Related Concept Videos

Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
8.3K
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
5.4K
Induced Pluripotent Stem Cells01:06

Induced Pluripotent Stem Cells

Stem cells are undifferentiated cells that divide and produce different cell types. Ordinarily, cells that have differentiated into a specific cell type are terminally differentiated; however, scientists have found a way to reprogram these mature cells so that they dedifferentiate and return to an unspecialized, proliferative state. These cells are pluripotent like embryonic stem cells—able to produce all cell types—and are called induced pluripotent stem cells (iPSCs).
Somatic...
5.9K
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
5.0K
Master Transcription Regulators02:23

Master Transcription Regulators

Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a  complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
8.0K
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
3.5K