Insights into established and emerging roles of SR protein family in plants and animals

Wang

et al. 2022

Viruses

Plant nucleotide-binding, leucine-rich, repeat-containing proteins (NLRs) play important roles in plant immunity. NLR expression and function are tightly regulated by multiple mechanisms. In this study, a conserved serine/arginine-rich protein (SR protein) was identified through the yeast one-hybrid screening of a tobacco cDNA library using DNA fragments from the N gene, an NLR that confers immunity to tobacco mosaic virus (TMV). This SR protein showed an interaction with a 3′ genomic regulatory sequence (GRS) and has a potential role in regulating the alternative splicing of N. Thus, it was named SR regulator for N, abbreviated SR4N. Further study showed that SR4N plays a positive role in N-mediated cell death but a negative role in N protein accumulation. SR4N also promotes multiple virus replications in co-expression experiments, and this enhancement may not function through RNA silencing suppression, as it did not enhance 35S-GFP expression in co-infiltration experiments. Bioinformatic and molecular studies revealed that SR4N belongs to the SR2Z subtype of the SR protein family, which was conserved in both dicots and monocots, and its roles in repressing viral immunity and triggering cell death were also conserved. Our study revealed new roles for SR2Z family proteins in plant immunity against viruses.

Section: Discussionmentioning

confidence: 99%

A Conserved, Serine-Rich Protein Plays Opposite Roles in N-Mediated Immunity against TMV and N-Triggered Cell Death

Wang

et al. 2022

Viruses

“…Among the 14 known SR proteins, SRSF1, SRSF4, SRSF5, SRSF6, and SRSF9 have one canonical RRM and one pseudo-RRM [ 26 ]. The main role of RRMs is to recognize specific pre-mRNA binding sites and dictate the position of SR proteins on RNA sequences [ 1 ]. A recent study has reported that the pseudo-RRM of SRSF1 frequently competes with splicing repressors, such as hnRNPA1, rather than recruiting spliceosomal components to regulate splicing [ 27 ].…”

Section: Biochemical Characteristics Of Sr Proteinsmentioning

confidence: 99%

“…Spliceosomes recognize the four major regulatory sequences in pre-mRNA introns, including the 5′ splice site (5′SS), the intron branch point site (BP), the 3′ splice site (3′SS), and the polypyrimidine tract [ 55 ]. SR proteins serve as molecular adapters to assemble spliceosomes and produce diverse pre-mRNAs in the splicing of transcripts [ 1 ]. Two major models have been proposed to explain the mechanism by which SR proteins affect cis-regulatory elements, called exonic splicing enhancers (ESEs), on pre-mRNAs to regulate exon inclusion (Fig.…”

Section: Functional Mechanisms Of Sr Proteins In Cancermentioning

confidence: 99%

See 1 more Smart Citation

SR proteins in cancer: function, regulation, and small inhibitor

Bei,

2024

Cell Mol Biol Lett

Alternative splicing of pre-mRNAs is a fundamental step in RNA processing required for gene expression in most metazoans. Serine and arginine-rich proteins (SR proteins) comprise a family of multifunctional proteins that contain an RNA recognition motif (RRM) and the ultra-conserved arginine/serine-rich (RS) domain, and play an important role in precise alternative splicing. Increasing research supports SR proteins as also functioning in other RNA-processing-related mechanisms, such as polyadenylation, degradation, and translation. In addition, SR proteins interact with N6-methyladenosine (m6A) regulators to modulate the methylation of ncRNA and mRNA. Dysregulation of SR proteins causes the disruption of cell differentiation and contributes to cancer progression. Here, we review the distinct biological characteristics of SR proteins and their known functional mechanisms during carcinogenesis. We also summarize the current inhibitors that directly target SR proteins and could ultimately turn SR proteins into actionable therapeutic targets in cancer therapy.

“…In addition to the important roles in constitutive and alternative splicing, SRSFs are also involved in various mRNA metabolism processes, such as mRNA export and stability, nonsense-mediated mRNA decay (NMD), translation, and many others. [52]. Instead of SRSFs, we identified a set of other splicing factors and spliceosome component genes under AS control, including members of hnRNPs.…”

Section: Trans-acting Factors Under As Control In Response To Environ...mentioning

confidence: 99%

Interplays between cis- and trans-Acting Factors for Alternative Splicing in Response to Environmental Changes during Biological Invasions of Ascidians

Huang,

Li,

Zhan

2023

IJMS

Alternative splicing (AS), a pivotal biological process contributing to phenotypic plasticity, creates a bridge linking genotypes with phenotypes. Despite its importance, the AS mechanisms underlying environmental response and adaptation have not been well studied, and more importantly, the cis- and trans-acting factors influencing AS variation remain unclear. Using the model invasive congeneric ascidians, Ciona robusta, and Ciona savignyi, we compared their AS responses to environmental changes and explored the potential determinants. Our findings unveiled swift and dynamic AS changes in response to environmental challenges, and differentially alternative spliced genes (DASGs) were functionally enriched in transmembrane transport processes. Interestingly, both the prevalence and level of AS in C. robusta were lower than those observed in C. savignyi. Furthermore, these two indices were higher under temperature stresses compared to salinity stresses in C. savignyi. All the observed patterns underscore the species-specific and environmental context-dependent AS responses to environmental challenges. The dissimilarities in genomic structure and exon/intron size distributions between these two species likely contributed to the observed AS variation. Moreover, we identified a total of 11 and 9 serine/arginine-rich splicing factors (SRSFs) with conserved domains and gene structures in the genomes of C. robusta and C. savignyi, respectively. Intriguingly, our analysis revealed that all detected SRSFs did not exhibit prevalent AS regulations. Instead, we observed AS control over a set of genes related to splicing factors and spliceosome components. Altogether, our results elucidate species-specific and environmental challenge-dependent AS response patterns in closely related invasive ascidians. The identified splicing factors and spliceosome components under AS control offer promising candidates for further investigations into AS-mediated rapid responses to environmental challenges complementary to SRSFs.