Molecular cloning of a novel secreted peptide, INM02, and regulation of its expression by glucose.
We report the identification of a novel secreted peptide, INM02. The mRNA transcript of human INM02 gene is about 3.0 kb. Its open-reading frame contains 762 bps and encodes a protein of 254 amino acids. Northern blot analysis demonstrates that INM02 mRNA is widely expressed in rat tissues, especially with abundant quantities in pancreatic islets, testis, and bladder tissue. We have expressed recombinant INM02 protein and generated rabbit anti-INM02 polyclonal antibodies. We show here that INM02 could be detectable in human serum by ELISA. We also present evidence that INM02 mRNA expression could be regulated by glucose. Experiments on both MIN6 cells and intact isolated islets demonstrate that INM02 mRNA levels are increased more than threefold by high glucose (25 mM) when compared with low glucose (5.5 mM). ELISA analysis shows that secretion of INM02 is significantly augmented by high glucose in vitro. It is speculated that as a novel secreted protein, INM02 is associated with functions of pancreatic islets, especially of beta-cells.
Wang
Xuanchun
X
Department of Endocrinology, Huashan Hospital, Institute of Endocrinology and Diabetology at Fudan University, Shanghai Medical College, Fudan University, Shanghai 200040, People's Republic of China.
Gong
Wei
W
Liu
Yu
Y
Yang
Zhihong
Z
Zhou
Wenbai
W
Wang
Mei
M
Yang
Zhen
Z
Wen
Jie
J
Hu
Renming
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D015870:Gene Expression / Q000502:physiology; D015723:Gene Library; D005947:Glucose / Q000502:physiology*; D006801:Humans; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000502:physiology*; D007340:Insulinoma; D008297:Male; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms; D021382:Protein Sorting Signals / Q000235:genetics*; D011506:Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000502:physiology; D001743:Urinary Bladder / Q000502:physiology
C543592:EMC10 protein, human; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D011506:Proteins; D012333:RNA, Messenger; D005947:Glucose