Endonuclein is a cell cycle regulated WD-repeat protein that is up-regulated in adenocarcinoma of the pancreas.
The transcript encoding endonuclein, the human homolog of yeast PWP1, was previously found up-regulated in pancreatic cancer tissue. By immunohistochemistry we detected a ubiquitous presence in several tissues examined: skin, liver, thyroid gland, heart muscle, neurons, kidney, bladder, pancreas, adrenal gland, ovary, uterus, testis and prostate gland. We especially noticed that normal pancreatic exocrine cells exhibited low protein levels while pancreatic adenocarcinoma cells revealed high levels. We found a heterogeneous subcellular distribution, especially with varying nuclear levels. In proliferating cells endonuclein protein expression and localization was cell cycle dependent, with increasing levels and nuclear focusing during the interphase toward mitosis. Ultrastructural analysis revealed ER and nuclear localization. Endonuclein contains five WD-repeats, indicating a putative role in crucial regulatory activities in the nucleus as well as in the ER.
Honoré
Bent
B
Department of Medical Biochemistry, Ole Worms Allé, Building 170, University of Aarhus, DK-8000 Aarhus C, Denmark. bh@biokemi.au.dk
Baandrup
Ulrik
U
Nielsen
Søren
S
Vorum
Henrik
H
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000276:immunology; D002460:Cell Line; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D007700:Kinetics; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins; D010179:Pancreas / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D020449:Repetitive Sequences, Amino Acid; D014018:Tissue Distribution; D015854:Up-Regulation
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C447901:PWP1 protein, human