P27 cis-regulatory element
Encyclopedia
The p27 cis-regulatory element is a structured G/C
rich RNA element
which is involved in controlling cell cycle
regulated translation
of the p27kip protein in human cells.
The p27kip1 protein is involved in cell cycle regulation and belongs to the Cip/Kip family of cyclin dependent kinase(CDK)inhibitors. These inhibitors possess an N-terminal CDK-inhibitory domain which binds to the ATP
binding pocket of the kinase and modulates its function.
This p27 cis-regulatory element is 114 nucleotides in length and is located at the very 5' end of the 5'UTR of the p27 mRNA. It contains a small open reading frame (ORF) of 29 amino acids which is preceded by and overlaps with a G/C-rich hairpin
domain. This hairpin domain is predicted to form multiple stable stem loops with similar free energy
. Both the open reading frame and the stem loop elements contribute to cell cycle-regulated translation of the p27 mRNA.
The structure of the G/C rich
element appears to be important to its regulatory function as replacement of the G/C rich region with an unstructured sequence has a greater effect on regulation of translation than a simple deletion of part of the G/C rich region. It has been suggested that cell cycle specific binding proteins may favour one of the predicted structures in the G/C region thereby promoting conformational states which could regulate downstream translation.
This element was initially characterised in human cells but has predicted homologs in mice and chickens.
GC-content
In molecular biology and genetics, GC-content is the percentage of nitrogenous bases on a DNA molecule that are either guanine or cytosine . This may refer to a specific fragment of DNA or RNA, or that of the whole genome...
rich RNA element
Cis-regulatory element
A cis-regulatory element or cis-element is a region of DNA or RNA that regulates the expression of genes located on that same molecule of DNA . This term is constructed from the Latin word cis, which means "on the same side as". These cis-regulatory elements are often binding sites for one or...
which is involved in controlling cell cycle
Cell cycle
The cell cycle, or cell-division cycle, is the series of events that takes place in a cell leading to its division and duplication . In cells without a nucleus , the cell cycle occurs via a process termed binary fission...
regulated translation
Translation
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...
of the p27kip protein in human cells.
The p27kip1 protein is involved in cell cycle regulation and belongs to the Cip/Kip family of cyclin dependent kinase(CDK)inhibitors. These inhibitors possess an N-terminal CDK-inhibitory domain which binds to the ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
binding pocket of the kinase and modulates its function.
This p27 cis-regulatory element is 114 nucleotides in length and is located at the very 5' end of the 5'UTR of the p27 mRNA. It contains a small open reading frame (ORF) of 29 amino acids which is preceded by and overlaps with a G/C-rich hairpin
Stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded DNA or, more commonly, in RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions,...
domain. This hairpin domain is predicted to form multiple stable stem loops with similar free energy
Thermodynamic free energy
The thermodynamic free energy is the amount of work that a thermodynamic system can perform. The concept is useful in the thermodynamics of chemical or thermal processes in engineering and science. The free energy is the internal energy of a system less the amount of energy that cannot be used to...
. Both the open reading frame and the stem loop elements contribute to cell cycle-regulated translation of the p27 mRNA.
The structure of the G/C rich
GC-content
In molecular biology and genetics, GC-content is the percentage of nitrogenous bases on a DNA molecule that are either guanine or cytosine . This may refer to a specific fragment of DNA or RNA, or that of the whole genome...
element appears to be important to its regulatory function as replacement of the G/C rich region with an unstructured sequence has a greater effect on regulation of translation than a simple deletion of part of the G/C rich region. It has been suggested that cell cycle specific binding proteins may favour one of the predicted structures in the G/C region thereby promoting conformational states which could regulate downstream translation.
This element was initially characterised in human cells but has predicted homologs in mice and chickens.