A serine kinase regulates intracellular localization of splicing factors in the cell cycle

• Published in: Nature (London) 1994-06, Vol.369 (6482), p.678-682
• Main Authors: Gui, Jian-Fang, Lane, William S, Fu, Xiang-Dong
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Arginine - metabolism; Base Sequence; Biological and medical sciences; cDNA; Cell Cycle; Cellular biology; cloning; Cloning, Molecular; DNA; Enzymes; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Fungal Proteins - metabolism; genes; HeLa Cells; Helminth Proteins - metabolism; Humanities and Social Sciences; Humans; letter; localization; man; Molecular Sequence Data; multidisciplinary; Nuclear Proteins - metabolism; nucleotide sequence; prediction; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; regulation; Ribonucleoproteins; Ribonucleoproteins, Small Nuclear - metabolism; RNA Splicing; role; Science; Science (multidisciplinary); Sequence Homology, Amino Acid; Serine - metabolism; serine kinase; Serine-Arginine Splicing Factors; splicing factors; SRPK1 protein; Transferases; Yeasts
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/369678a0

SMALL nuclear ribonucleoprotein particles (snRNPs) and non-snRNP splicing factors containing a serine/arginine-rich domain (SR proteins) concentrate in ‘speckles’ in the nucleus of interphase cells 1 . It is believed that nuclear speckles act as storage sites for splicing factors while splicing occurs on nascent transcripts 2 . Splicing factors redistribute in response to transcription inhibition 3,4 or viral infection 5 , and nuclear speckles break down and reform as cells progress through mitosis 6 . We have now identified and cloned a kinase, SRPK1, which is regulated by the cell cycle and is specific for SR proteins; this kinase is related to a Caenorhabditis elegans kinase and to the fission yeast kinase Dskl (ref. 7). SRPK1 specifically induces the disassembly of nuclear speckles, and a high level of SRPK1 inhibits splicing in vitro . Our results indicate that SRPK1 may have a central role in the regulatory network for splicing, controlling the intranuclear distribution of splicing factors in interphase cells, and the reorganization of nuclear speckles during mitosis.