Cloning and characterization of a novel endoplasmic reticulum localized G-patch domain protein, IER3IP1.
The endoplasmic reticulum (ER) is the site of protein synthesis, folding, post-translational modifications and export. The ER membrane and its lumen contain various chaperones and enzymes that are involved in every aspect of the ER function. In this report, we identified a novel endoplasmic reticulum protein (immediate early response 3 interacting protein 1, IER3IP1) during the large-scale partial sequencing of a liver cDNA library. The full-length 1304 bp IER3IP1 cDNA has a predicted open reading frame (ORF), which encodes an 82 amino-acid protein possessing a G-patch domain. This domain is found in several RNA associated proteins and has been suggested to be involved in RNA binding. IER3IP1 gene was mapped to the chromosome 18q12 by radiation hybrid analysis. In northern blot hybridization, it was shown that IER3IP1 gene has a high expression in heart, skeletal muscle and kidney, a moderate expression in liver and brain and a low expression in placenta, lung and peripheral blood leukocyte. With the presence of transmembrane domain at the C-terminal, the translated IER3IP1 protein was localized to endoplasmic reticulum of HepG2 cells and was confirmed by co-localization with ER specific marker.
Department of Biochemistry, The Chinese University of Hong Kong, Mong Man Wai Building, Shatin, N.T., Hong Kong, China.
Wai Han
WH
Yiu
Jodie Wing Ming
JW
Poon
Stephen Kwok Wing
SK
Tsui
Kwok Pui
KP
Fung
Mary Miu Yee
MM
Waye
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D021101:Radiation Hybrid Mapping; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D002352:Carrier Proteins; D018076:DNA, Complementary; C492451:IER3IP1 protein, human; D008164:Luminescent Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins