Liangliang Sun
Michigan State University, MI·Chemistry
One gene can give rise to many slightly different protein molecules called proteoforms. Each may differ through alternative processing or added chemical tags (post-translational modifications).
- Fields
Chemistry
Biochemistry
Biology
- Topics
top-down proteomics
proteoforms
capillary electrophoresis-mass spectrometry
- Grants
- 2 known grants, through Apr 2029
What they work on
- Advance CE-MS top-down proteomics to build a first draft proteoform atlas of HeLa cells. The atlas will contain at least one intact protein form for every protein-coding gene.
- Develop CE-MS methods that measure intact proteins from a few or even single human cells. This would let researchers study cell-to-cell differences.
- Identify proteoforms that control early cell differentiation and zygotic genome activation, when the embryo turns on its own genes. Use quantitative top-down proteomics of zebrafish embryos and blastomeres.
- Build new analytical tools to raise top-down proteomics sensitivity about tenfold for small samples. Apply them to compare colorectal cancer cells before and after metastasis to find proteoform changes.
- Use quantitative top-down proteomics of Lynch syndrome tumors to reveal how mutations in DNA mismatch repair genes act at the level of intact protein forms.
More about the research
These versions can have very different jobs, yet most protein studies first chop proteins into small pieces, which loses this information. Top-down proteomics instead measures whole, intact proteins. Two projects develop more sensitive tools for this approach using capillary electrophoresis-mass spectrometry (CE-MS). CE-MS separates molecules in a thin capillary tube and then weighs them precisely in a mass spectrometer. The projects then apply these tools to early embryo development and colorectal cancer.
Why it matters
Colorectal cancer kills tens of thousands of people in the United States each year. Measuring intact protein forms in CRC cells and tumors could reveal proteoform biomarkers of metastasis. It could also clarify how faulty DNA repair genes drive Lynch syndrome, which may point to better therapies. A human proteoform atlas and single-cell methods could also give cancer, developmental and brain researchers a resource for studying how cells differ.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Si Wu
University of Alabama, AL·Chemistry
Develop and benchmark a 2D-RPLC-CE-MS/MS platform, which combines two separation steps with mass spectrometry, to screen intact proteoforms globally in single ovarian cancer spheroids.
Ryan Julian
University of California-Riverside, CA·Chemistry
Design and synthesize photoactivated chemical modifiers that install a weak link at chosen residues in a protein backbone, so the protein can be split at that spot on demand.
Upasna Sharma
University of California-Santa Cruz, CA·Biology
Determine whether Mettl7a1, a predicted RNA methyltransferase that adds methyl tags to RNA, is needed for minor zygotic genome activation and normal early development in mouse preimplantation embryos.
The school
Michigan State University: 28 labs on PI Pages, $932M a year on research, 555 research doctorates a year.
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