Isolation and
Characterization of a Novel Transcript of Hepatopoietin
Lü Jun，XU Wang-Xiang1，ZHAN Yi-Qun1，CUI Xiao-Lin1，CAI Wei-Min，HE Fu-Chu1，YANG Xiao-Ming1*
( Institute of Infectious Disease, First Affiliated Hospital, Medical
School, Zhejiang University, Hangzhou 310003, China; 1Institute
of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850,
China )
Abstract A novel
transcript of human HPO (HPO-205) encoding a 205 amino acidORF corresponding to
a translated product of 23 kD different from the previous HPO that lacks the
N-terminal 80 amino acids, was
isolated from human fetal liver cDNA library by 5- RACE methods. The
dose-dependent stimulation of DNA synthesis of HepG2 hepatoma cells by HPO-205
demonstrated its similar biological activity with HPO in vitro. The
level of MAPK (mitogen-activated protein kinase)phosphorylation was further
examined by Western blot analysis and the result revealed that HPO-205 protein
might have stronger activity on stimulating hepatic cell proliferation than
that of HPO. The similar result was observed by FACS technique. Therefore, our results suggest that the HPO-205
has activity to stimulate proliferation of liver derived cells, and this
activity may be stronger than HPO.
Key words hepatopoietin (HPO); cell proliferation;
MAPK; HPO-205
*Corresponding author: Tel, 86-10-66931424; Fax, 86-10-68214653; e-mail, [email protected]