Signal peptide of eosinophil cationic protein upregulates transforming growth factor-alpha expression in human cells.
Eosinophil cationic protein (ECP) is a major component of eosinophil granule protein that is used as a clinical bio-marker for asthma and allergic inflammatory diseases. Previously, it has been reported that the signal peptide of human ECP (ECPsp) inhibits the cell growth of Escherichia coli (E. coli) and Pichia pastoris (P. pastoris), but not mammalian A431 cells. The inhibitory effect is due to the lack of human signal peptide peptidase (hSPP), a protease located on the endoplasmic reticulum (ER) membrane, in the lower organisms. In this study, we show that the epidermal growth factor receptor (EGFR) is upregulated by the exogenous ECPsp-eGFP as a result of the increased expression of the transforming growth factor-alpha (TGF-alpha) at both transcriptional and translational levels in A431 and HL-60 clone 15 cell lines. Furthermore, the N-terminus of ECPsp fragment generated by the cleavage of hSPP (ECPspM1-G17) gives rise to over threefold increase of TGF-alpha protein expression, whereas another ECPsp fragment (ECPspL18-A27) and the hSPP-resistant ECPsp (ECPspG17L) do not show similar effect. Our results indicate that the ECPspM1-G17 plays a crucial role in the upregulation of TGF-alpha, suggesting that the ECPsp not only directs the secretion of mature ECP, but also involves in the autocrine system.
Chang
Hao-Teng
HT
Institute of Molecular and Cellular Biology & Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.
Kao
Yu-Lin
YL
Wu
Chia-Mao
CM
Fan
Tan-Chi
TC
Lai
Yiu-Kay
YK
Huang
Kai-Ling
KL
Chang
Yuo-Sheng
YS
Tsai
Jaw-Ji
JJ
Chang
Margaret Dah-Tsyr
MD
D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D047150:Eosinophil Cationic Protein / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D021382:Protein Sorting Signals / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000494:pharmacology; D016211:Transforming Growth Factor alpha / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D017077:Culture Media, Conditioned; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D016211:Transforming Growth Factor alpha; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D066246:ErbB Receptors; D047150:Eosinophil Cationic Protein; C479220:RNASE3 protein, human; D016282:Aspartic Acid Endopeptidases; C460085:signal peptide peptidase