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Updated: Nov 25, 2025
Laser Microdissection-Based Protocol for the LC-MS/MS Analysis of the Proteomic Profile of Neuromelanin Granules
Published on: December 16, 2021
Proteomic analysis on the regulation of DOPA-melanin synthesis in Talaromyces marneffei
Xiaoyue He1, Donghua Liu2, Qicong Chen3
1Department of Dermatology and Venereology, First Affiliated Hospital,Guangxi Medical University, Nanning, Guangxi, 530021, China.
Background:
Yeast form of T.marneffei can produce DOPA-melanin which perform an important role in the pathogen surviving in macrophage. So far, the proteomic associated with melanin synthesis remain unclearly in T.marneffei.
Methods:
The whole yeast cell proteins were extracted from T.marneffei cultured with or without l-DOPA. Using two-dimensional gel electrophoresis combined with MALDI-TOF mass spectrometry, distinguished proteins were identified between T.marneffei cultured with or without l-DOPA. Furthermore, geldanamycin were used to assess the inhibition effect on T.marneffei melanin production in vitro.
Results:
16 distinguished proteins were identified in DOPA-melanized yeast cells, as well as 15 triple-up-expressed proteins and 7 triple-down-expressed proteins in comparison with non DOPA-melanized yeast cells. Of note, proteins differentially expressed proteins were predominantly heat shock proteins. HSP90/60/70 genes expressions increased significantly demonstrated by q-RT-PCR, which was consistent with the proteomics changes. GO analysis showed that the majority of differentially expressed proteins including HSPs(especially HSP90) were found enriched in stress response, cellular process, protein folding, stimuli response and biological process. KEGG pathway analysis showed that proteins were enriched predominantly in phagosome. HSP90 inhibitor(Geldanamycin) inhibited the brown-black pigment production of T.marneffei yeast grown on brain heart infusion agar, as well as the inhibition effect was observed by transmission electron microscope.
Conclusions:
The results demonstrates that HSP90 palys an essential role in T.marneffei DOPA-melanin synthesis pathway.
Insights
Heat shock protein 90 (HSP90) is crucial for DOPA-melanin synthesis in T.marneffei, aiding pathogen survival. Inhibiting HSP90 reduces melanin production, offering potential therapeutic targets.
Area of Science:
- Mycology
- Pathogen Biology
- Proteomics
Background:
- The yeast form of T. marneffei produces DOPA-melanin, essential for survival within macrophages.
- The proteomic landscape of melanin synthesis in T. marneffei remains poorly understood.
Purpose of the Study:
- To investigate the proteomic changes associated with DOPA-melanin synthesis in T. marneffei.
- To identify key proteins involved in the melanin production pathway.
- To assess the role of heat shock proteins, particularly HSP90, in T. marneffei melanization.
Main Methods:
- Proteomic analysis using 2D gel electrophoresis and MALDI-TOF MS on T. marneffei yeast cultured with and without L-DOPA.
- Quantitative reverse transcription PCR (q-RT-PCR) to analyze heat shock protein gene expression.
- In vitro inhibition assays using Geldanamycin, an HSP90 inhibitor, and transmission electron microscopy.
Main Results:
- 16 differentially expressed proteins were identified in DOPA-melanized cells, with heat shock proteins (HSPs) being predominant.
- HSP90, HSP60, and HSP70 gene expression significantly increased, correlating with proteomic findings.
- HSP90 inhibition by Geldanamycin effectively reduced DOPA-melanin production in T. marneffei.
Conclusions:
- Heat shock protein 90 (HSP90) plays a critical role in the DOPA-melanin synthesis pathway in T. marneffei.
- The findings highlight the importance of HSP90 in fungal pathogen survival and virulence.
- Targeting HSP90 may represent a viable strategy to combat T. marneffei infections.
