What role does histone phosphorylation play in chromosome behavior during meiosis?
Recent research on histone phosphorylation has demonstrated that nearly all histone types are phosphorylated at specific residues and that these modifications act as a critical intermediate step in chromosome condensation during cell division, transcriptional regulation, and DNA damage repair.
What does the H3 histone do?
Histone H3, and hence the chromatin, is thus a key factor transmitting the tension status to the spindle assembly checkpoint. During mitosis, chromatin goes through significant compaction and condensation to form metaphase chromosomes for segregation.
How does histone methylation affect transcription?
Methylation and demethylation of histones turns the genes in DNA “off” and “on,” respectively, either by loosening their tails, thereby allowing transcription factors and other proteins to access the DNA, or by encompassing their tails around the DNA, thereby restricting access to the DNA.
Can histone tails be phosphorylated?
All four nucleosomal histone tails contain acceptor sites that can be phosphorylated by a number of protein kinases and dephosphorylated by phosphatases.
How does histone modification affect gene expression?
Both DNA and histone proteins are prone to methylation, while acetylation is associated only with histones. These two modifications frequently govern the gene expression pattern in a cell by altering between transcriptional activation and repression.
How does histone deacetylation affect gene expression?
Deacetylation performed by HDAC molecules has the opposite effect. By deacetylating the histone tails, the DNA becomes more tightly wrapped around the histone cores, making it harder for transcription factors to bind to the DNA. This leads to decreased levels of gene expression and is known as gene silencing.
What is the role of histone H3 ser-10 phosphorylation during apoptosis?
Collectively, these findings suggest that PKCδ is the kinase responsible for histone H3 Ser-10 phosphoryation during apoptosis and thus contributes to chromatin condensation together with other apoptosis-related histone modifications. As a result, histone H3 Ser-10 phosphorylation can be designated a new ‘apoptotic histone code’ mediated by PKCδ.
Is histone H3 phosphorylation a mitotic marker?
Phosphorylation of histone H3 on Ser-10 is regarded as an epigenetic mitotic marker and is tightly correlated with chromosome condensation during both mitosis and meiosis.
Can histone proteins regulate nucleosome structure during apoptosis?
Post-translational modifications of histone proteins have the ability to regulate nucleosome structure. Chromatin condensation and DNA fragmentation are the most prominent nuclear features that occur during apoptotic cell death.
How does pro-apoptotic kinase protein kinase C (PKC) mediate histone H3 ser-10 phosphorylation?
Here we report that histone H3 Ser-10 phosphorylation is mediated by the pro-apoptotic kinase protein kinase C (PKC) δ during apoptosis. We observed that PKCδ robustly phosphorylates histone H3 on Ser-10 both in vitro and in vivo. Ectopic expression of catalytically active PKCδ efficiently induces condensed chromatin structure in the nucleus.