Revolutionizing cancer treatment: a comprehensive review of CAR-T cell therapy.

Chimeric antigen receptor (CAR)-T cell therapy is a promising new treatment for cancer that involves genetically modifying a patient's T-cells to recognize and attack cancer cells. This review provides an overview of the latest discoveries and clinical trials related to CAR-T cell therapy, as well as the concept and applications of the therapy. The review also discusses the limitations and potential side effects of CAR-T cell therapy, including the high cost and the risk of cytokine release syndrome and neurotoxicity. While CAR-T cell therapy has shown promising results in the treatment of hematologic malignancies, ongoing research is needed to improve the efficacy and safety of the therapy and expand its use to solid tumors. With continued research and development, CAR-T cell therapy has the potential to revolutionize cancer treatment and improve outcomes for patients with cancer.

The Phantom Mark: Enigmatic roles of phospho-Threonine 4 modification of the C-terminal domain of RNA polymerase II.

The largest subunit of RNA polymerase II (Pol II) has an unusual carboxyl-terminal domain (CTD). This domain is composed of a tandemly repeating heptapeptide, Y1 S2 P3 T4 S5 P6 S7 , that has multiple roles in regulating Pol II function and processing newly synthesized RNA. Transient phosphorylation of Ser2 and Ser5 of the YS2 PTS5 PS repeat have well-defined roles in recruiting different protein complexes and coordinating sequential steps in gene transcription. As such, these phospho-marks encipher a molecular recognition code, colloquially termed the CTD code. In contrast, the contribution of phospho-Threonine 4 (pThr4/pT4) to the CTD code remains opaque and contentious. Fuelling the debate on the relevance of this mark to gene expression are the findings that replacing Thr4 with a valine or alanine has varied impact on cellular function in different species and independent proteomic analyses disagree on the relative abundance of pThr4 marks. Yet, substitution with negatively charged residues is lethal and even benign mutations selectively disrupt synthesis and 3' processing of distinct sets of coding and non-coding transcripts. Suggestive of non-canonical roles, pThr4 marked Pol II regulates distinct gene classes in a species- and signal-responsive manner. Hinting at undiscovered roles of this elusive mark, multiple signal-responsive kinases phosphorylate Thr4 at target genes. Here, we focus on this under-explored residue and postulate that the pThr4 mark is superimposed on the canonical CTD code to selectively regulate expression of targeted genes without perturbing genome-wide transcriptional processes. This article is categorized under: RNA Processing > 3' End Processing RNA Processing > Processing of Small RNAs RNA Processing > Splicing Regulation/Alternative Splicing.

Sequence, structural and functional conservation among the human and fission yeast ELL and EAF transcription elongation factors.

BACKGROUND: Transcription elongation is a dynamic and tightly regulated step of gene expression in eukaryotic cells. Eleven nineteen Lysine rich Leukemia (ELL) and ELL Associated Factors (EAF) family of conserved proteins are required for efficient RNA polymerase II-mediated transcription elongation. Orthologs of these proteins have been identified in different organisms, including fission yeast and humans. METHODS AND RESULTS: In the present study, we have examined the sequence, structural and functional conservation between the fission yeast and human ELL and EAF orthologs. Our computational analysis revealed that these proteins share some sequence characteristics, and were predominantly disordered in both organisms. Our functional complementation assays revealed that both human ELL and EAF proteins could complement the lack of ell1+ or eaf1+ in Schizosaccharomyces pombe respectively. Furthermore, our domain mapping experiments demonstrated that both the amino and carboxyl terminal domains of human EAF proteins could functionally complement the S. pombe eaf1 deletion phenotypes. However, only the carboxyl-terminus domain of human ELL was able to partially rescue the phenotypes associated with lack of ell1+ in S. pombe. CONCLUSIONS: Collectively, our work adds ELL-EAF to the increasing list of human-yeast complementation gene pairs, wherein the simpler fission yeast can be used to further enhance our understanding of the role of these proteins in transcription elongation and human disease.

Arabidopsis thaliana possesses two novel ELL associated factor homologs.

Transcription elongation is one of the key steps at which RNA polymerase II-directed expression of protein-coding genes is regulated in eukaryotic cells. Different proteins have been shown to control this process, including the ELL/EAF family. ELL Associated Factors (EAFs) were first discovered in a yeast two-hybrid screen as interaction partners of the human ELL (Eleven nineteen Lysine-rich Leukemia) transcription elongation factor. Subsequently, they have been identified in different organisms, including Schizosaccharomyces pombe. However, no homolog(s) of EAF has as yet been characterized from plants. In the present work, we identified EAF orthologous sequences in different plants and have characterized two novel Arabidopsis thaliana EAF homologs, AtEAF-1 (At1g71080) and AtEAF-2 (At5g38050). Sequence analysis showed that both AtEAF-1 and AtEAF-2 exhibit similarity with its S. pombe EAF counterpart. Moreover, both Arabidopsis thaliana and S. pombe EAF orthologs share conserved sequence characteristic features. Computational tools also predicted a high degree of disorder in regions towards the carboxyl terminus of these EAF proteins. We demonstrate that AtEAF-2, but not AtEAF-1 functionally complements growth deficiencies of Schizosaccharomyces pombe eaf mutant. We also show that only AtEAF-1 displays transactivation potential resembling the S. pombe EAF ortholog. Subsequent expression analysis in A. thaliana showed that both homologs were expressed at varying levels during different developmental stages and in different tissues tested in the study. Individual null-mutants of either AtEAF-1 or AtEAF-2 are developmentally normal implying their functional redundancy. Taken together, our results provide first evidence that A. thaliana also possesses functional EAF proteins, suggesting an evolutionary conservation of these proteins across organisms.

Schizosaccharomyces pombe Pol II transcription elongation factor ELL functions as part of a rudimentary super elongation complex.

ELL family transcription factors activate the overall rate of RNA polymerase II (Pol II) transcription elongation by binding directly to Pol II and suppressing its tendency to pause. In metazoa, ELL regulates Pol II transcription elongation as part of a large multisubunit complex referred to as the Super Elongation Complex (SEC), which includes P-TEFb and EAF, AF9 or ENL, and an AFF family protein. Although orthologs of ELL and EAF have been identified in lower eukaryotes including Schizosaccharomyces pombe, it has been unclear whether SEC-like complexes function in lower eukaryotes. In this report, we describe isolation from S. pombe of an ELL-containing complex with features of a rudimentary SEC. This complex includes S. pombe Ell1, Eaf1, and a previously uncharacterized protein we designate Ell1 binding protein 1 (Ebp1), which is distantly related to metazoan AFF family members. Like the metazoan SEC, this S. pombe ELL complex appears to function broadly in Pol II transcription. Interestingly, it appears to have a particularly important role in regulating genes involved in cell separation.

Structure function characterization of the ELL Associated Factor (EAF) from Schizosaccharomyces pombe.

EAF (ELL Associated Factor) proteins interact with the transcription elongation factor, ELL (Eleven nineteen Lysine rich Leukemia) and enhance its ability to stimulate RNA polymerase II-mediated transcriptional elongation in vitro. Schizosaccharomyces pombe contains a single homolog of EAF (SpEAF), which is not essential for survival of S. pombe in contrast to its essential higher eukaryotic homologs. The physiological role of SpEAF is not well understood. In this study, we show that S. pombe EAF is important in regulating growth of S. pombe cells during normal growth conditions. Moreover, SpEAF is also essential for survival under conditions of DNA damage, while its deletion does not affect growth under environmental stress conditions. Our in vivo structure-function studies further demonstrate that while both the amino and carboxyl terminal domains of SpEAF possess the potential to activate transcription, only the amino terminal domain of SpEAF is involved in interaction with the S. pombe ELL protein. The carboxyl-terminus of SpEAF is required for rescue of the growth defect under normal and DNA damaging conditions that is associated with the absence of SpEAF. Using bioinformatics and circular dichroism spectroscopy, we show that the carboxyl-terminus of SpEAF has a disordered conformation. Furthermore, addition of trifluoroethanol triggered its transition from a disordered to α-helical conformation. Taken together, the results presented here identify novel structural and functional features of SpEAF protein, providing insights into how EAF proteins may enforce transcriptional control of gene expression.

The amino-terminal domain of ELL transcription elongation factor is essential for ELL function in Schizosaccharomyces pombe.

Transcriptional elongation is a critical step for regulating expression of protein-coding genes. Multiple transcription elongation factors have been identified in vitro, but the physiological roles of many of them are still not clearly understood. The ELL (Eleven nineteen Lysine rich Leukemia) family of transcription elongation factors are conserved from fission yeast to humans. Schizosaccharomyces pombe contains a single ELL homolog (SpELL) that is not essential for its survival. Therefore to gain insights into the in vivo cellular functions of SpELL, we identified phenotypes associated with deletion of ell1 in S. pombe. Our results demonstrate that SpELL is required for normal growth of S. pombe cells. Furthermore, cells lacking ell1+ exhibit a decrease in survival when exposed to DNA-damaging conditions, but their growth is not affected under environmental stress conditions. ELL orthologs in different organisms contain three conserved domains, an amino-terminal domain, a middle domain and a carboxyl-terminal domain. We also carried out an in vivo functional mapping of these conserved domains within S. pombe ELL and uncovered a critical role for its amino-terminus in regulating all its cellular functions, including growth under different conditions, transcriptional elongation potential and interaction with S. pombe EAF. Taken together our results suggest that the domain organization of ELL proteins is conserved across species, but the in vivo functions as well as the relationship between the various domains and roles of ELL show species-specific differences.