The nuclear ATPase/adenylate kinase hCINAP is recruited to perinucleolar caps generated upon RNA pol.II inhibition.
hCINAP is an atypical nucleoplasmic enzyme, combining structural features of adenylate kinases and ATPases, which exhibits dual enzymatic activity. It interacts with the Cajal Body marker coilin and its level of expression and enzymatic activity influence Cajal Body numbers. Here we show that upon specific transcriptional inhibition of RNA pol.II, hCINAP segregates in perinuclear caps identified as Dark Nucleolar Caps (DNCs). These are distinct from perinucleolar caps where coilin and fibrillarin (both Cajal Body components) accumulate. In DNCs, hCINAP co-localizes with Paraspeckle Protein (PSP1) and also co-segregates with PSP1, and not coilin, in nuclear and nucleolar foci upon UV irradiation.
Malekkou
Anna
A
Department of Biological Sciences, University of Cyprus and Cyprus Institute of Neurology and Genetics, P.O. Box 20537, 1678 Nicosia, Cyprus.
Lederer
Carsten W
CW
Lamond
Angus I
AI
Santama
Niovi
N
D021581:Active Transport, Cell Nucleus / Q000528:radiation effects; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000263:Adenylate Kinase / Q000378:metabolism*; D002466:Cell Nucleolus / Q000378:metabolism* / Q000528:radiation effects; D006367:HeLa Cells; D006801:Humans; D012319:RNA Polymerase II / Q000378:metabolism*; D014466:Ultraviolet Rays
D000263:Adenylate Kinase; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases