RESUMO
CENP-A determines the identity of the centromere. Because the position and size of the centromere and its number per chromosome must be maintained, the distribution of CENP-A is strictly regulated. In this study, we have aimed to understand mechanisms to regulate the distribution of CENP-A (Cnp1SP) in fission yeast. A mutant of the ufd1+ gene (ufd1-73) encoding a cofactor of Cdc48 ATPase is sensitive to Cnp1 expressed at a high level and allows mislocalization of Cnp1. The level of Cnp1 in centromeric chromatin is increased in the ufd1-73 mutant even when Cnp1 is expressed at a normal level. A preexisting mutant of the cdc48+ gene (cdc48-353) phenocopies the ufd1-73 mutant. We have also shown that Cdc48 and Ufd1 proteins interact physically with centromeric chromatin. Finally, Cdc48 ATPase with Ufd1 artificially recruited to the centromere of a mini-chromosome (Ch16) induce a loss of Cnp1 from Ch16, leading to an increased rate of chromosome loss. It appears that Cdc48 ATPase, together with its cofactor Ufd1 remove excess Cnp1 from chromatin, likely in a direct manner. This mechanism may play a role in centromere disassembly, a process to eliminate Cnp1 to inactivate the kinetochore function during development, differentiation, and stress response.
Assuntos
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Cromatina/genética , Cromatina/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteína Centromérica A/genética , Proteína Centromérica A/metabolismo , Histonas/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Centrômero/genética , Centrômero/metabolismo , Adenosina Trifosfatases/metabolismo , Extratos Vegetais/metabolismoRESUMO
The centromere proteins (CENPs), a critical mitosis-related protein complexes, are involved in the kinetochore assembly and chromosome segregation. In this study, we identified that CENPA was significantly up-regulated in HCC and highly expressed CENPA correlated with poor prognosis for HCC patients. Knockdown of CENPA inhibited HCC cell proliferation and tumor growth in vitro and in vivo. Mechanistically, CENPA transcriptionally activated and cooperated with YY1 to drive the expression of cyclin D1 (CCND1) and neuropilin 2 (NRP2). Moreover, we identified that CENPA can be lactylated at lysine 124 (K124). The lactylation of CENPA at K124 promotes CENPA activation, leading to enhanced expression of its target genes. In summary, CENPA function as a transcriptional regulator to promote HCC via cooperating with YY1. Targeting the CENPA-YY1-CCND1/NRP2 axis may provide candidate therapeutic targets for HCC.
Assuntos
Carcinoma Hepatocelular , Proteína Centromérica A , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Histonas , Neoplasias Hepáticas/metabolismo , Fator de Transcrição YY1/genética , Proteína Centromérica A/metabolismoRESUMO
Investigations into the epigenetic status of individual cells within tissues can produce both epigenetic data for different cell types and positional information of the cells. Thus, these investigations are important for understanding the intra- and inter-cellular control systems of developmental and environmental responses in plants. However, a simple method to detect epigenetic modifications of individual cells in plant tissues is not yet available because detection of the modifications requires immunohistochemistry using specific antibodies. In this study, we developed a simple immunohistochemical method that does not require sectioning to investigate epigenetic modifications. This method uses a clearing system to detect methylated histones, acetylated histones, methylated DNA and/or centromeric histone H3 variants. Analyses of four dicots and five monocots indicated that this method provides a universal technique to investigate epigenetic modifications in diverse plant species.