What is Haemoglobin gene expression controlled by?
The switches from ε to γ and from γ to β globin gene expression are controlled exclusively at the transcriptional level [1]. The ζ to α switch is controlled predominantly at the transcriptional level, although posttranscriptional mechanisms also play a role [2].
How are hemoglobin genes expressed?
Hemoglobin gene expression is restricted to erythroid cells. The genes are expressed at extremely high levels late in erythroid differentiation, with balanced production of α-globin and β-globin. Paralogous globin genes are expressed at progressive developmental stages.
What factor regulates the globin gene?
PYR is an adult stage–specific factor that binds to a pyrimidine-rich DNA stretch between the γ- and β-globin genes from where it might repress γ-globin and activate β-globin gene expression. Deletion of the PYR element determines a prolonged and delayed switching.
What is the role of the globin gene?
The globins are a superfamily of heme-containing globular proteins, involved in binding and/or transporting oxygen. These proteins all incorporate the globin fold, a series of eight alpha helical segments. Two prominent members include myoglobin and hemoglobin.
What is the function of globin in hemoglobin?
How is the expression of genes regulated or controlled?
Gene expression is primarily controlled at the level of transcription, largely as a result of binding of proteins to specific sites on DNA. The regulator gene codes for synthesis of a repressor molecule that binds to the operator and blocks RNA polymerase from transcribing the structural genes.
What do you mean by regulation of gene expression?
Gene regulation is the process of controlling which genes in a cell’s DNA are expressed (used to make a functional product such as a protein). Different cells in a multicellular organism may express very different sets of genes, even though they contain the same DNA.
Is globin and globulin the same?
Globin and globulins are major proteins of an organism. Globulins are a major type of blood proteins found in serum. They are responsible for several functions of the blood. The key difference between globin and globulin is that globins are heme-containing globular proteins while globulins are simple globular proteins.
What can bind to globin?
Globins contain a heme prosthetic group (Fe-protoporphyrin IX), by which they can reversibly bind gaseous ligands like O2, CO, and NO. Most known globins fulfill respiratory functions, supplying the cell with adequate amounts of O2 for aerobic energy production via the respiratory chain in the mitochondria [5–7].