
Yie-Hwa Chang, Ph.D.
Associate Professor
Understanding how two distinct eukaryotic methionine aminopeptidases (MetAPs) function in the amino terminal processing of eukaryotic proteins and its role in angiogenesis.
Research Interests
Our lab is interested in understanding how two distinct eukaryotic methionine aminopeptidases (MetAPs) function in the amino-terminal processing of eukaryotic proteins and its role in angiogenesis. Recently, the type-2 MetAP was found to be the molecular target for angiogenesis inhibitors, TNP-470 and ovalicin. Angiogenesis is the process of new blood vessel formation. It plays very important roles in both physiological states and a variety of pathological states.
Recent Publications
Advances in Quantitative Techniques for Mapping RNA Modifications
Advances in Quantitative Techniques for Mapping RNA Modifications
RNA modifications are essential regulators of gene expression and cellular function, modulating RNA stability, splicing, translation, and localization. Dysregulation of these modifications has been linked to cancer, neurodegenerative disorders, viral infections, and other diseases. Precise quantification and mapping of RNA modifications are crucial for understanding their biological roles. This review summarizes current and emerging methodologies for RNA modification analysis, including mass spectrometry, antibody-based and non-antibody-based approaches, PCR- and NMR-based detection, chemical- and enzyme-assisted sequencing, and nanopore direct RNA sequencing. We also highlight advanced techniques for single-cell and single-molecule imaging, enabling the study of modification dynamics and cellular heterogeneity. The advantages, limitations, and challenges of each method are discussed, providing a framework for selecting appropriate analytical strategies. Future perspectives emphasize high-throughput, multiplexed, and single-cell approaches, integrating multiple technologies to decode the epitranscriptome. These approaches form a robust toolkit for uncovering RNA modification functions, discovering biomarkers, and developing novel therapeutic strategies.
Impact of Protein N-Modifications on Cellular Functions and Human Health
Impact of Protein N-Modifications on Cellular Functions and Human Health
Most human proteins are modified by enzymes that act on the α-amino group of a newly synthesized polypeptide. Methionine aminopeptidases can remove the initiator methionine and expose the second amino acid for further modification by enzymes responsible for myristoylation, acetylation, methylation, or other chemical reactions. Specific acetyltransferases can also modify the initiator methionine and sometimes the acetylated methionine can be removed, followed by further modifications. These modifications at the protein N-termini play critical roles in cellular protein localization, protein-protein interaction, protein-DNA interaction, and protein stability. Consequently, the dysregulation of these modifications could significantly change the development and progression status of certain human diseases. The focus of this review is to highlight recent progress in our understanding of the roles of these modifications in regulating protein functions and how these enzymes have been used as potential novel therapeutic targets for various human diseases.
Pathophysiology and Biomarker Potential of Fatty Acid Ethyl Ester Elevation During Alcoholic Pancreatitis
Pathophysiology and Biomarker Potential of Fatty Acid Ethyl Ester Elevation During Alcoholic Pancreatitis
The role of fatty acid ethyl esters (FAEEs) during human alcoholic pancreatitis is unknown. We compared FAEEs levels with their nonesterified fatty acids (NEFAs) precursors during alcohol intoxication and clinical alcoholic pancreatitis. The pathophysiology underlying FAEEs increase and their role as diagnostic biomarkers for alcoholic pancreatitis was investigated.
Resilience buffers the effects of sleep problems on the trajectory of suicidal ideation from adolescence through young adulthood
Resilience buffers the effects of sleep problems on the trajectory of suicidal ideation from adolescence through young adulthood
To examine both the between-person and within-person effects of sleep problems on the trajectory of suicidal ideation from ages 14 to 22 and investigate whether resilience moderates the effects. Age and sex differences were explored in the main and interaction effects of sleep problems and resilience on suicidal ideation.
Proteomic Analysis of Human Immune Responses to Live-Attenuated Tularemia Vaccine
Proteomic Analysis of Human Immune Responses to Live-Attenuated Tularemia Vaccine
() is an intracellular pathogen that causes a potentially debilitating febrile illness known as tularemia. can be spread by aerosol transmission and cause fatal pneumonic tularemia. If untreated, mortality rates can be as high as 30%. To study the host responses to a live-attenuated tularemia vaccine, peripheral blood mononuclear cell (PBMC) samples were assayed from 10 subjects collected pre- and post-vaccination, using both the 2D-DIGE/MALDI-MS/MS and LC-MS/MS approaches. Protein expression related to antigen processing and presentation, inflammation (PPARγ nuclear receptor), phagocytosis, and gram-negative bacterial infection was enriched at Day 7 and/or Day 14. Protein candidates that could be used to predict human immune responses were identified by evaluating the correlation between proteome changes and humoral and cellular immune responses. Consistent with the proteomics data, parallel transcriptomics data showed that MHC class I and class II-related signals important for protein processing and antigen presentation were up-regulated, further confirming the proteomic results. These findings provide new biological insights that can be built upon in future clinical studies, using live attenuated strains as immunogens, including their potential use as surrogates of protection.
