looking for a postdoc lab

Yanfeng Wang yanfeng at mail.med.upenn.edu
Sat Oct 31 17:32:42 EST 1998

My friend in China is looking for a place to do postdoc. The following is
his C.V. Any information is appreciated.

Yuqing Dong                           Telephone:86-10-62751855
Room 2045,Building 48
Peking University
Beijing 100871,P.R.China                  E-mail: dong at pubms.pku.edu.cn

Personal Information
Sex: male
Birth: Dec 5, 1971
Marital status: single

Seeking a postdoctoral position in Biochemistry, Molecular
Biology,Genetics or Cell biology

* Currently Ph.D. candidate in Molecular Biology (Expected date of
graduation in June,1999).            Peking University,Beijing,P.R.China
* B.S.in Biochemistry(June,1994).East China University of Science and
Technology,Shanghai city,P.R.China

Special Training
DNA cloning and sequencing, construction and screening of  cDNA library,
PCR amplification in any condition, southern/northern blot, procaryotic
expression of cloned genes, cell culture, protein separation and
purification, detection and function analysis, immuno-techniques, western
blot etc.

Working Experience
During my persuing the Ph.D degree, I was engaged in the study of cytokins
in our lab. Our lab opens up cytokins as medicine in combination with a
famous medical Biotechnical company, such as IL-6,IL-11,IL-12,IL-18 and
GM-CSF etc. Owning to my very experienced and talented, I participated in
all the work, especially in the cloning of genes, overexpression and
purification of these proteins, and in the testing of the activity of
cytokins. Now, these cytokins I mentioned above have been put in
production in the factory. Because many of my work took much economic
benefit to the company, I won the award due to my outstanding devotion.
In the course of my working, I realize that cytokins are in a system, in
which cytokins connect each other. In macrocosm, this connection reflects
overlapping function. So, I think the more understanding the relationship
of cytokins, the more useful to human beings. It's very important to
concentrate the research on the net of cytokins.

"Studies on the Mechanism of hetR Gene Regulating Heterocyst
Differentiation in Cyanobacteria"
This study deals with the function and mechanism of HetR protein in the
heterocyst differentiation in cyanobacteria.
Heterocysts are the special differentiated cells in some of the
filamentous cyanobacteria carrying nitrogen fixation. They are formed when
the growth media is depleted of combined nitrogen. It has been confirmed
that the hetR gene is a switch regulatory gene controlling heterocyst
differentiation and development.
According to the work in our lab, the HetR was suggested as a serine-type
protease, so that it was most important to determine which Ser in HetR is
the active site. There are three Ser in HetR protein, which are Ser142,Ser
152 and Ser179. Site-specific mutagenesis was performed and every mutated
protein was overproduced. The result showed that the Ser152 is the active
residue of HetR.
In addition, rHetR always forms dimer and there is a Cys residue in HetR.
To identify if the Cys45 is the binding site with other protein in vivo,
the site-specific mutagenesis was perform and the mutant protein was
Now, the four mutant genes have been cloned into suitable vectors and
ready to be transferred into a cyanobacteria without any hetR background.
We are going to learn more about the mechanism of hetR gene regulating
heterocyst differentiation in cyanobacteria.
Proteinase have been shown to play very important role in the regulation
of cell differentiation and development in organisms from bacteria to
animals, our results showed that HetR is probably an enzyme with an active
Ser residue. The study of this kind of proteinase is in progress.
There has been no report concerning a convient plasmid for gene expressing
in cyanobacteria. I constructed one plasmid by using pBBR1mcs which is a
broad-host plasmid and pET3a. The results showed that it worked well in
both E.coli and  cyanobacteria. There is a ntcA gene in cyanobacteria,
which can inhibit the differentiation of heterocyst where it dosen't
function. As far as we know, hetR gene also controls the differentiation
of heterocyst. Using the new vector, I am prepared to transfer hetR gene
into a kind of cyanobacteria ntcA(-), which has a nonfunctional ntcA gene
to examine if the differentiation of heterocyst will occus.

1. Dong Y,Zhou R,Yang F and Zhao J(1998) Identification of the active
serine of the HetR protein. In Procedings of 2nd Chinese Plant molecular
Biology(Lin Z, ed). KeXue Press,Beijing.In press

2. Zhou R,Dong Y and Zhao J(1998) Biochemical charaterization of the HetR
protein from Anabaena sp. 7120. In proceedings of 9th International
Symposium of Photosynthetic Prokaryotes(G.Schmitterer ed).Plumtum
Publisher,New york.pp247-252

3. Zhou R,Wei X,Jiang N,Li H,Dong Y,Hsi K and Zhao J(1998)Evidence that
HetR Protein is an unusual Serine-type Protease. Proc Natl Acad Sci, Usa

4. Dong Y,Zhou R,Wei X,Jiang N and Zhao J, "Charaterization of HetR
protein of   anabaena pcc 7120" (to be submitted)

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