^{Protein Networks} 

Project leader: Dr. Chun-Ming Liu

Many small peptides are very important signal molecules in plants and animals. It has been found in animals that many small peptides are used in endocrine (such as growth hormone, prolactin and thyrotrophin) and neural communication (such as gastrin, insulin, HYP, opioid, secretin and tachykinin).

In plants, a handful peptide ligands have been found.  The signal of the peptide ligand is received by receptor kinase complexes in the neighboring cells, leading to downstream phosphorylation steps to switch on and off certain genes. The figure here shows the CLV3 signaling pathway which controls plant apical meristem.

These peptides are often derived from larger peptides after post-translational processing, which could not be studied by traditional Western blotting and expression analysis including cDNA microarray. The technology development in proteomics in the recent years provides a unique way to study peptide ligands and their signalling pathways. Two equipments used in our proteomic research are MALDI-TOF and Q-TOF mass spectrometry. Q-TOF can be used for both peptide profiling and de novo sequencing.

Instead of 2-D electrophoresis based protein separation, we use chromatography to fractionate the peptides based on their charges, molecular masses and hydrophobicity.  Using these tools we perform peptide analysis in plant meristem and microspore embryogenesis medium to identify and to characterize the general molecular machinery of peptide signalling in plants. To facilitate the analysis we developed a automated peptide identification protocol.  One of the genes we are interested in is LIGAND-LIKE PROTEIN 1 (LLP1) that is expressed in cotyledon primordia during embryogenesis.

For further information, please contact:
Dr. Chun-Ming Liu
Plant Research International
PO Box 16, 6700 Wageningen
The Netherlands
Tel: 31-317-477330
Fax: 310-317-423110
Email: chunming.liu@wur.nl 

Related Links:

Proteomic related Journals

Literatures: