Psödouridin Sentaz 7 Enziminin Eksikliği Maya Hücrelerini DNA Hasar Ajanlarına Karşı Duyarlı Hale Getirir

Year 2025, Volume: 8 Issue: 4, 1613 - 1623, 16.09.2025

Mehmet Tardu

https://doi.org/10.47495/okufbed.1615403

Abstract

RNA modifikasyonları, RNA moleküllerinin kimyasını değiştirmede önemli bir rol oynayarak onların yapılarını, işlevselliklerini ve kararlılıklarını etkiler. Bugüne kadar yapılan çalışmalarda çeşitli RNA türleri üzerinde 160’tan fazla farklı modifikasyon tipi tanımlanmıştır. Bu modifikasyonlardan biri, uridin (U) molekülünün psödouridin (Ψ) formuna enzimatik dönüşümüdür ve bu süreç, psödouridin sentaz (Pus) enzimleri tarafından gerçekleştirilir. Bu modifikasyon, hem kodlama yapan RNA (mRNA) hem de kodlama yapmayan RNA (ncRNA) türlerinde bulunur. Bu dönüşümden sorumlu enzimler arasında, Pus7 belirli gelişimsel ve fiziksel durumlarla ilişkilendirilmesi nedeniyle öne çıkmaktadır. Araştırmalar, Pus7’nin zihinsel yetersizlikler, gecikmiş konuşma gelişimi, mikrosefali ve kısa boy gibi durumlarla bağlantılı olduğunu göstermektedir. Bu rahatsızlıklarla ilişkisine rağmen, Pus7’nin tam biyolojik rolü ve mekanizması yeterince anlaşılmış değildir ve bu durum daha fazla araştırmaya olanak tanımaktadır. Bu çalışmada, Saccharomyces cerevisiae hücrelerinde Pus7’nin DNA hasar stresine karşı rolünü anlamayı amaçladık. Bu amaçla, yabanıl tip ve pus7Δ hücreleri, ultraviyole (UV) ışığı ve metil metansülfonat (MMS) gibi DNA hasarına neden olan ajanların farklı konsantrasyonlarına maruz bırakıldı. Sağ kalım eğri analizleri ve okta ekim sonuçları, pus7Δ hücrelerinin 2 mM MMS ve 15 j/m² UV ışığı varlığında büyüme kusurları sergilediğini gösterdi. Bu sonuçlar, Pus7 enziminin yokluğunun maya hücrelerini DNA hasarına neden olan ajanlara duyarlı hale getirdiğini ortaya koymaktadır. Sonuçlar bize, birçok kanser türünün ayırt edici özelliği olan genomik dengesizliğe katkıda bulunan DNA hasarı stresi altında Pus7'nin rolünü araştırmak için acilen kapsamlı araştırmalara ihtiyaç duyulduğunu göstermektedir.

Keywords

Saccharomyces cerevisiae , Psödouridin sentaz , Pus7 , Metil metansülfonat , Ultraviyole ışık , DNA hasarı

Lack of Pseudouridine Synthase 7 Enzyme Sensitizes Yeast Cells to DNA-Damaging Agents

Abstract

RNA modifications are essential in reshaping the chemistry of RNA molecules, influencing their structure, function, and stability. Up to now, more than 160 different types of modifications have been discovered among different RNA species. One prominent modification is the enzymatic transformation of uridine (U) into pseudouridine (Ψ), a process facilitated by pseudouridine synthase (Pus) enzymes, which occurs in both coding (mRNA) and non-coding (ncRNA) RNA species. Among the enzymes responsible for this transformation, Pus7 stands out due to its association with certain developmental and physical conditions. Research links Pus7 to intellectual disabilities, delayed speech development, microcephaly, and short stature. Despite its association with these disorders, the exact biological role and mechanism of Pus7 remain poorly understood, leaving room for further investigation. In this study, we aimed to understand the role of Pus7 in Saccharomyces cerevisiae cells under DNA damage stress. To achieve this, wild-type and pus7Δ cells were subjected to varying concentrations of DNA-damaging agents, including ultraviolet (UV) light and the chemical methyl methanesulfonate (MMS). Survival curves and spot plating assay results demonstrated that pus7Δ cells exhibit growth defects when exposed to 2 mM MMS or 15 J/m² UV light. These findings indicate that the absence of Pus7 enzyme renders yeast cells sensitive to DNA-damaging agents. Further research is necessary to investigate the role of Pus7 under DNA damage stress, which contributes to genomic instability - a hallmark of many cancers.

Keywords

Saccharomyces cerevisiae , Pseudouridine synthase , Pus7 , Methyl methanesulfonate , Ultraviolet light , DNA damage

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