PRMT1 arginine methyltransferase accumulates in cytoplasmic bodies that respond to selective inhibition and DNA damage

Abstract

Protein arginine methyltransferases (PRMTs) are responsible for symmetric and asymmetric methylation of arginine residues of nuclear and cytoplasmic proteins. In the nucleus, PRMTs belong to important chromatin modifying enzymes of immense functional significance that affect gene expression, splicing and DNA repair. By time-lapse microscopy we have studied the sub-cellular localization and kinetics of PRMT1 after inhibition of PRMT1 and after irradiation. Both transiently expressed and endogenous PRMT1 accumulated in cytoplasmic bodies that were located in the proximity of the cell nucleus. The shape and number of these bodies were stable in untreated cells. However, when cell nuclei were microirradiated by UV-A, the mobility of PRMT1 cytoplasmic bodies increased their, size was reduced, and they disappeared within approximately 20 min. The same response occurred after γ-irradiation of the whole cell population, but with delayed kinetics. Treatment with PRMT1 inhibitors induced disintegration of these PRMT1 cytoplasmic bodies and prevented formation of 53BP1 nuclear bodies (NBs) that play a role during DNA damage repair. The formation of 53BP1 NBs was not influenced by PRMT1 over-expression. Taken together, we show that PRMT1 concentrates in cytoplasmic bodies, which respond to DNA injury in the cell nucleus, and to treatment with various PRMT1 inhibitors.

Complex interactomes and post-translational modifications of the regulatory proteins HABP4 and SERBP1 suggest pleiotropic cellular functions

“…Other HABP4 interactors also have functions related to DNA damage. PRMT1, for example, has a function related to the DNA damage response, once it accumulates in cytoplasmic bodies responsive to DNA damage[71]. The protein inhibitor of activated STAT (PIAS) also interacts with HABP4 and when over-expressed in HeLa cells promoted higher resistance to ionizing radiation through its involvement in the repair pathways HR and NHEJ[72].…”

UVI-induced endogenous retrovirus HERV-E λ 4-1 expression in blood mononuclear cells

“…УФО-излучение сопровождается многочисленными изменениями ýпигенетической регуляции ýкспрессии генов. С одной стороны, глобальным ацетилированием гистонов, с другой -локальным гипоацетилированием Н3-гистона и р300, опосредованным воздействием на уровень метилирования ДНК-увеличением мобильности и уменьшением размера частиц протеин-аргинин метилтрансфераз, ответственных за метилирование остатков аргинина [35], увеличением ýкспрессии 5-метилцитозина, вовлеченного в гидроксиметилирование ДНК [36], а также прямым изменением уровня метилирования CpG [37].…”

Advanced Image Acquisition and Analytical Techniques for Studies of Living Cells and Tissue Sections

“…Early S and late S-phases were also evaluated using the distribution pattern of blue fluorescent protein (BFP)-PCNA (blue) in HeLa cells; late S-phase is characterized by PCNA accumulation at only nuclear and nucleolar periphery. The irradiation conditions by UVA laser was adopted according to the study by Bartová et al (2011) or Šustáčková et al (2012). …”

“…The protein kinetics at locally induced DNA lesions can be further analyzed through the FRAP technique. Moreover, FRET can reveal novel protein interactions at the DNA lesions induced in different compartments of the nucleus, including heterochromatin, euchromatin or in the nucleolus (Šustáčková et al, 2012; Stixová et al, 2014 b ). As an example, we have studied the primary transcription factor (TF) of the nucleolus, upstream binding factor 1 (UBF1), and we have observed its accumulation at both the UVA-irradiated nucleoli and the surrounding chromatin, which were also positive for high levels of HP1 β .…”

“…Subsequently, many other FPs, which cover the entire spectrum of visible light, have been discovered (Campbell et al, 2002;Shaner et al, 2007;Subach et al, 2008;Shcherbo et al, 2009). These proteins provide immense biological value, particularly for live-cell studies that are designed to evaluate cell fate after cell division or various cell treatments, including interventions that affect the epigenome through the inhibition or activation of histone-modifying enzymes (Nagy & Soutoglou, 2009;Stixová et al, 2012;Suchánková et al, 2014).…”