scholarly journals Characterization and comparison of four serine- and arginine-rich (SR) protein kinases

1997 ◽  
Vol 326 (3) ◽  
pp. 693-700 ◽  
Author(s):  
Oliver NAYLER ◽  
Stefan STAMM ◽  
Axel ULLRICH
Keyword(s):  
Alternative Splicing ◽  
Catalytic Domain ◽  
Expression Patterns ◽  
Sr Proteins ◽  
Amino Acid Sequences ◽  
Sr Protein ◽  
High Sequence Identity ◽  
Mouse Tissues ◽  
Transformed Cell Lines

Phosphorylated serine- and arginine-rich (SR) proteins are components of the spliceosomal complex, and have been implicated in the control of alternative splicing. Kinases that regulate the phosphorylation and possibly the intranuclear distribution of SR proteins may therefore contribute to changes in choice of splice site. We have cloned three mouse cDNAs with high sequence identity to the family of LAMMER kinases (i.e. kinases carrying the conserved signature EHLAMMERILG in the catalytic domain). A comparison of their amino acid sequences revealed two related subfamilies with high evolutionary conservation. We have compared the expression patterns of these proteins in mouse tissues and transformed cell lines with that of a previously cloned family member (mCLK1/STY), and detected various transcripts for each gene. This underlines previous findings of alternative splicing of mclk1/STY. Our results suggest that the proportions of products for each gene are regulated independently. We further demonstrate that all variants encode autophosphorylating proteins that can phosphorylate several biochemically purified SR proteins in vitro, leading to hyperphosphorylation of at least one SR protein in vivo. The observed tissue distributions and substrate specificities suggest that these kinases may all be constituents of a network of regulatory mechanisms that enable SR proteins to control RNA splicing.

scholarly journals Alternative splicing variants of dual specificity tyrosine phosphorylated and regulated kinase 1B exhibit distinct patterns of expression and functional properties

2003 ◽  
Vol 372 (3) ◽  
pp. 881-888 ◽  
Author(s):  
Susanne LEDER ◽  
Hanna CZAJKOWSKA ◽  
Barbara MAENZ ◽  
Katrin de GRAAF ◽  
Andreas BARTHEL ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Protein Kinases ◽  
Kinase Activity ◽  
Catalytic Domain ◽  
Expression Patterns ◽  
Neuronal Cell ◽  
Dual Specificity ◽  
Mouse Tissues ◽  
Splicing Variants

The dual specificity tyrosine phosphorylated and regulated kinase (DYRK) family of protein kinases is a group of evolutionarily conserved protein kinases that have been characterized as regulators of growth and development in mammals, Drosophila and lower eukaryotes. In the present study, we have characterized three splicing variants of DYRK1B (DYRK1B-p65, DYRK1B-p69 and DYRK1B-p75) with different expression patterns and enzymic activities. DYRK1B-p65 and DYRK1B-p69 exhibited similar, but not identical, patterns of expression in mouse tissues, with the highest protein levels found in the spleen, lung, brain, bladder, stomach and testis. In contrast, DYRK1B-p75 was detected specifically in skeletal muscles, in the neuronal cell line GT1-7 and also in differentiated, adipocyte-like 3T3-L1 cells, but not in undifferentiated 3T3-L1 preadipocytes. A comparison of the mouse and human Dyrk1b genomic and cDNA sequences defined the alternative splicing events that produce the variants of DYRK1B. In DYRK1B-p75, transcription starts with exon 1B instead of exon 1A, generating a new translation start, which extends the open reading frame by 60 codons. This gene structure suggests that alternative promoters direct the expression of DYRK1B-p69 and DYRK1B-p75. Both splicing variants exhibited kinase activity in vitro and contained phosphotyrosine when expressed in COS-7 cells. Owing to differential recognition of the 3′-splice site in exon 9, DYRK1B-p65 differs from DYRK1B-p69 by the absence of 40 amino acids within the catalytic domain. DYRK1B-p65 lacked kinase activity in vitro and did not contain phosphotyrosine. DYRK1B-p69 and DYRK1B-p75 stimulated reporter gene activity driven by the forkhead in rhabdosarcoma (FKHR)-dependent glucose-6-phosphatase promoter more strongly when compared with DYRK1B-p65, indicating that the DYRK1B splicing variants exhibit functional differences.

scholarly journals Akt2 Regulation of Cdc2-Like Kinases (Clk/Sty), Serine/Arginine-Rich (SR) Protein Phosphorylation, and Insulin-Induced Alternative Splicing of PKCβII Messenger Ribonucleic Acid

Endocrinology ◽  
2008 ◽  
Vol 150 (5) ◽  
pp. 2087-2097 ◽  
Author(s):  
Kun Jiang ◽  
Niketa A. Patel ◽  
James E. Watson ◽  
Hercules Apostolatos ◽  
Eden Kleiman ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Protein Phosphorylation ◽  
Kinase Inhibitors ◽  
Sr Proteins ◽  
Null Mouse ◽  
Phosphatidylinositol 3 Kinase ◽  
Sr Protein ◽  
Messenger Ribonucleic Acid ◽  
Extracellular Signals ◽  
Mouse Tissues

Serine/arginine-rich (SR) proteins play essential roles in the constitutive and regulated splicing of precursor mRNAs. Phosphorylation of the arginine/serine dipeptide-rich (RS) domain by SR protein kinases such as Cdc2-like kinases (Clk/Sty) modulates their subcellular localization and activation. However, it remains unclear how these kinases and their target SR proteins are regulated by extracellular signals. Regulation of protein kinase C βII (PKCβII) pre-mRNA alternative splicing via exon inclusion by Akt2, a central kinase in insulin action, involves phosphorylation of SR proteins. Here we showed that Akt2, in response to insulin, resulted in phosphorylation of Clk/Sty, which then altered SR protein phosphorylation in concert with Akt2. Insulin-stimulated PKCβII pre-mRNA splicing was blocked by Clk/Sty and phosphatidylinositol-3-kinase inhibitors, and diabetic Akt2-null mouse tissues had impaired phospho-Clk/Sty, SR protein phosphorylation, and PKCβII expression. Furthermore, we observed that Akt2 phosphorylated several SR proteins distinct from Clk/Sty in response to insulin. Akt2-catalyzed phosphorylation of Clk/Sty and SR proteins revealed a role for both kinases in splicing regulation indicating dual functions for Akt2 in response to insulin in this pathway.

scholarly journals Functional properties of p54, a novel SR protein active in constitutive and alternative splicing.

1996 ◽  
Vol 16 (10) ◽  
pp. 5400-5408 ◽  
Author(s):  
W J Zhang ◽  
J Y Wu
Keyword(s):  
Alternative Splicing ◽  
Splice Site ◽  
Sr Proteins ◽  
Dependent Manner ◽  
Sr Protein ◽  
Protein Protein Interaction ◽  
Small Nuclear Ribonucleoprotein ◽  
S100 Extract ◽  
U2 Auxiliary Factor ◽  
Auxiliary Factor

The p54 protein was previously identified by its reactivity with an autoantiserum. We report here that p54 is a new member of the SR family of splicing factors, as judged from its structural, antigenic, and functional characteristics. Consistent with its identification as an SR protein, p54 can function as a constitutive splicing factor in complementing splicing-deficient HeLa cell S100 extract. However, p54 also shows properties distinct from those of other SR family members, p54 can directly interact with the 65-kDa subunit of U2 auxiliary factor (U2AF65), a protein associated with the 3' splice site. In addition, p54 interacts with other SR proteins but does not interact with the U1 small nuclear ribonucleoprotein U1-70K or the 35-kDa subunit of U2 auxiliary factor (U2AF35). This protein-protein interaction profile is different from those of prototypical SR proteins SC35 and ASF/SF2, both of which interact with U1-70K and U2AF35 but not with U2AF65. p54 promotes the use of the distal 5' splice site in E1A pre-mRNA alternative splicing, while the same site is suppressed by ASF/SF2 and SC35. These findings and the differential tissue distribution of p54 suggest that this novel SR protein may participate in regulation of alternative splicing in a tissue- and substrate-dependent manner.

scholarly journals A plethora of plant serine/arginine-rich proteins: redundancy or evolution of novel gene functions?

2004 ◽  
Vol 32 (4) ◽  
pp. 561-564 ◽  
Author(s):  
M. Kalyna ◽  
A. Barta
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Environmental Control ◽  
Expression Patterns ◽  
Ectopic Expression ◽  
Sr Proteins ◽  
Sr Protein ◽  
Duplication Events ◽  
Intron Recognition ◽  
Alternatively Spliced

Precursor-mRNA (pre-mRNA) processing is an important step in gene expression and its regulation leads to the expansion of the gene product repertoire. SR (serine-arginine)-rich proteins are key players in intron recognition and spliceosome assembly and significantly contribute to the alternative splicing process. Due to several duplication events, at least 19 SR proteins are present in the Arabidopsis genome, which is almost twice as many as in humans. They fall into seven different subfamilies, three of them homologous with metazoan splicing factors, whereas the other four seem to be specific for plants. The current results show that most of the duplicated genes have different spatiotemporal expression patterns indicating functional diversification. Interestingly, most of the SR protein genes are alternatively spliced and in some cases this process was shown to be under developmental and/or environmental control. This might greatly influence gene expression of target genes as also exemplified by ectopic expression studies of particular SR proteins.

scholarly journals Interactions between two fission yeast serine/arginine-rich proteins and their modulation by phosphorylation

2002 ◽  
Vol 368 (2) ◽  
pp. 527-534 ◽  
Author(s):  
Zhaohua TANG ◽  
Norbert F. KÄUFER ◽  
Ren-Jang LIN
Keyword(s):  
Alternative Splicing ◽  
Protein Phosphorylation ◽  
Fission Yeast ◽  
Protein Function ◽  
Sr Proteins ◽  
Specific Protein ◽  
Glutathione S Transferase ◽  
Sr Protein ◽  
Random Screen ◽  
Related Proteins

The unexpected low number of genes in the human genome has triggered increasing attention to alternative pre-mRNA splicing, and serine/arginine-rich (SR) proteins have been correlated with the complex alternative splicing that is a characteristic of metazoans. SR proteins interact with RNA and splicing protein factors, and they also undergo reversible phosphorylation, thereby regulating constitutive and alternative splicing in mammals and Drosophila. However, it is not clear whether the features of SR proteins and alternative splicing are present in simple and genetically tractable organisms, such as yeasts. In the present study, we show that the SR-like proteins Srp1 and Srp2, found in the fission yeast Schizosaccharomyces pombe, interact with each other and the interaction is modulated by protein phosphorylation. By using Srp1 as bait in a yeast two-hybrid analysis, we specifically isolated Srp2 from a random screen. This Srp interaction was confirmed by a glutathione-S-transferase pull-down assay. We also found that the Srp1—Srp2 complex was phosphorylated at a reduced efficiency by a fission yeast SR-specific kinase, Dis1-suppression kinase (Dsk1). Conversely, Dsk1-mediated phosphorylation inhibited the formation of the Srp complex. These findings offer the first example in fission yeast for interactions between SR-related proteins and the modulation of the interactions by specific protein phosphorylation, suggesting that a mammalian-like SR protein function may exist in fission yeast.

scholarly journals Roles for SR Proteins and hnRNP A1 in the Regulation of c-src Exon N1

2003 ◽  
Vol 23 (6) ◽  
pp. 1874-1884 ◽  
Author(s):  
Nanette Rooke ◽  
Vadim Markovtsov ◽  
Esra Cagavi ◽  
Douglas L. Black
Keyword(s):  
Regulatory Element ◽  
Sr Proteins ◽  
Hnrnp A1 ◽  
Sr Protein ◽  
Enhancer Element ◽  
Splicing Regulators ◽  
In Vitro Splicing ◽  
Hnrnp F

ABSTRACT The splicing of the c-src exon N1 is controlled by an intricate combination of positive and negative RNA elements. Most previous work on these sequences focused on intronic elements found upstream and downstream of exon N1. However, it was demonstrated that the 5′ half of the N1 exon itself acts as a splicing enhancer in vivo. Here we examine the function of this regulatory element in vitro. We show that a mutation in this sequence decreases splicing of the N1 exon in vitro. Proteins binding to this element were identified as hnRNP A1, hnRNP H, hnRNP F, and SF2/ASF by site-specific cross-linking and immunoprecipitation. The binding of these proteins to the RNA was eliminated by a mutation in the exonic element. The activities of hnRNP A1 and SF2/ASF on N1 splicing were examined by adding purified protein to in vitro splicing reactions. SF2/ASF and another SR protein, SC35, are both able to stimulate splicing of c-src pre-mRNA. However, splicing activation by SF2/ASF is dependent on the N1 exon enhancer element whereas activation by SC35 is not. In contrast to SF2/ASF and in agreement with other systems, hnRNP A1 repressed c-src splicing in vitro. The negative activity of hnRNP A1 on splicing was compared with that of PTB, a protein previously demonstrated to repress splicing in this system. Both proteins repress exon N1 splicing, and both counteract the enhancing activity of the SR proteins. Removal of the PTB binding sites upstream of N1 prevents PTB-mediated repression but does not affect A1-mediated repression. Thus, hnRNP A1 and PTB use different mechanisms to repress c-src splicing. Our results link the activity of these well-known exonic splicing regulators, SF2/ASF and hnRNP A1, to the splicing of an exon primarily controlled by intronic factors.

scholarly journals Roles of hnRNP A1, SR Proteins, and p68 Helicase in c-H-ras Alternative Splicing Regulation

2003 ◽  
Vol 23 (8) ◽  
pp. 2927-2941 ◽  
Author(s):  
Sònia Guil ◽  
Renata Gattoni ◽  
Montserrat Carrascal ◽  
Joaquín Abián ◽  
James Stévenin ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Sr Proteins ◽  
Splicing Regulation ◽  
Hnrnp A1 ◽  
Carboxy Terminus ◽  
Extracellular Signals ◽  
Nuclear Extracts ◽  
Acting In Concert

ABSTRACT Human ras genes play central roles in coupling extracellular signals with complex intracellular networks controlling proliferation, differentiation, and apoptosis, among others processes. c-H-ras pre-mRNA can be alternatively processed into two mRNAs due to the inclusion or exclusion of the alternative exon IDX; this renders two proteins, p21H-Ras and p19H-RasIDX, which differ only at the carboxy terminus. Here, we have characterized some of the cis-acting sequences and trans-acting factors regulating IDX splicing. A downstream intronic silencer sequence (rasISS1), acting in concert with IDX, negatively regulates upstream intron splicing. This effect is mediated, at least in part, by the binding of hnRNP A1. Depletion and add-back experiments in nuclear extracts have confirmed hnRNP A1's inhibitory role in IDX splicing. Moreover, the addition of two SR proteins, SC35 and SRp40, can counteract this inhibition by strongly promoting the splicing of the upstream intron both in vivo and in vitro. Further, the RNA-dependent helicase p68 is also associated with both IDX and rasISS1 RNA, and suppression of p68 expression in HeLa cells by RNAi experiments results in a marked increase of IDX inclusion in the endogenous mRNA, suggesting a role for this protein in alternative splicing regulation.

Identification of the chitinase genes from the diamondback moth, Plutella xylostella

2016 ◽  
Vol 106 (6) ◽  
pp. 769-780 ◽  
Author(s):  
Z.H. Liao ◽  
T.C. Kuo ◽  
C.H. Kao ◽  
T.M. Chou ◽  
Y.H. Kao ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Catalytic Domain ◽  
Diamondback Moth ◽  
Expression Patterns ◽  
Reproductive Potential ◽  
Amino Acid Sequences ◽  
Phylogenetic Groups ◽  
Rapid Amplification ◽  
Chitinase Genes ◽  
Cruciferous Plants

AbstractChitinases have an indispensable function in chitin metabolism and are well characterized in numerous insect species. Although the diamondback moth (DBM) Plutella xylostella, which has a high reproductive potential, short generation time, and characteristic adaptation to adverse environments, has become one of the most serious pests of cruciferous plants worldwide, the information on the chitinases of the moth is presently limited. In the present study, using degenerated polymerase chain reaction (PCR) and rapid amplification of cDNA ends-PCR strategies, four chitinase genes of P. xylostella were cloned, and an exhaustive search was conducted for chitinase-like sequences from the P. xylostella genome and transcriptomic database. Based on the domain analysis of the deduced amino acid sequences and the phylogenetic analysis of the catalytic domain sequences, we identified 15 chitinase genes from P. xylostella. Two of the gut-specific chitinases did not cluster with any of the known phylogenetic groups of chitinases and might be in a new group of the chitinase family. Moreover, in our study, group VIII chitinase was not identified. The structures, classifications and expression patterns of the chitinases of P. xylostella were further delineated, and with this information, further investigations on the functions of chitinase genes in DBM could be facilitated.

scholarly journals Dsk1p kinase phosphorylates SR proteins and regulates their cellular localization in fission yeast

2007 ◽  
Vol 405 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Zhaohua Tang ◽  
Amy Tsurumi ◽  
Sarah Alaei ◽  
Christopher Wilson ◽  
Cathleen Chiu ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Fission Yeast ◽  
Cellular Localization ◽  
Sr Proteins ◽  
Regulatory Function ◽  
General Mechanism ◽  
Nuclear Targeting ◽  
Sr Protein ◽  
Eukaryotic Organism

Evolutionarily conserved SR proteins (serine/arginine-rich proteins) are important factors for alternative splicing and their activity is modulated by SRPKs (SR protein-specific kinases). We previously identified Dsk1p (dis1-suppressing protein kinase) as the orthologue of human SRPK1 in fission yeast. In addition to its similarity of gene structure to higher eukaryotes, fission yeast Schizosaccharomyces pombe is a unicellular eukaryotic organism in which alternative splicing takes place. In the present study, we have revealed for the first time that SR proteins, Srp1p and Srp2p, are the in vivo substrates of Dsk1p in S. pombe. Moreover, the cellular localization of the SR proteins and Prp2p splicing factor is dependent on dsk1+: Dsk1p is required for the efficient nuclear localization of Srp2p and Prp2p, while it promotes the cytoplasmic distribution of Srp1p, thereby differentially influencing the destinations of these proteins in the cell. The present study offers the first biochemical and genetic evidence for the in vivo targets of the SRPK1 orthologue, Dsk1p, in S. pombe and the significant correlation between Dsk1p-mediated phosphorylation and the cellular localization of the SR proteins, providing information about the physiological functions of Dsk1p. Furthermore, the results demonstrate that the regulatory function of SRPKs in the nuclear targeting of SR proteins is conserved from fission yeast to human, indicating a general mechanism of reversible phosphorylation to control the activities of SR proteins in RNA metabolism through cellular partitioning.

scholarly journals Regulation of Alternative Splicing by SRrp86 and Its Interacting Proteins

2003 ◽  
Vol 23 (21) ◽  
pp. 7437-7447 ◽  
Author(s):  
Jun Li ◽  
Ian C. Hawkins ◽  
Christopher D. Harvey ◽  
Jennifer L. Jennings ◽  
Andrew J. Link ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Sr Proteins ◽  
Splicing Factors ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Protein Activity ◽  
Splice Site Selection ◽  
Sr Protein ◽  
Library Screen ◽  
Specific Proteins

ABSTRACT SRrp86 is a unique member of the SR protein superfamily containing one RNA recognition motif and two serine-arginine (SR)-rich domains separated by an unusual glutamic acid-lysine (EK)-rich region. Previously, we showed that SRrp86 could regulate alternative splicing by both positively and negatively modulating the activity of other SR proteins and that the unique EK domain could inhibit both constitutive and alternative splicing. These functions were most consistent with the model in which SRrp86 functions by interacting with and thereby modulating the activity of target proteins. To identify the specific proteins that interact with SRrp86, we used a yeast two-hybrid library screen and immunoprecipitation coupled to mass spectrometry. We show that SRrp86 interacts with all of the core SR proteins, as well as a subset of other splicing regulatory proteins, including SAF-B, hnRNP G, YB-1, and p72. In contrast to previous results that showed activation of SRp20 by SRrp86, we now show that SAF-B, hnRNP G, and 9G8 all antagonize the activity of SRrp86. Overall, we conclude that not only does SRrp86 regulate SR protein activity but that it is, in turn, regulated by other splicing factors to control alternative splice site selection.

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