Progerin
Encyclopedia
Progerin is a truncated version of lamin A protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 involved in Hutchinson-Gilford progeria syndrome. Progerin is most often generated by a silent point mutation (C1824T) in the lamin A gene, LMNA. This mutation activates a cryptic splice site and gives rise to a form of lamin A with a deletion of 50 amino acids near the C-terminus. Approximately
80% of Hutchinson-Gilford progeria syndrome cases are heterozygous for this silent
Silent mutation
Silent mutations are DNA mutations that do not result in a change to the amino acid sequence of a protein. They may occur in a non-coding region , or they may occur within an exon in a manner that does not alter the final amino acid sequence...

 point mutation
Point mutation
A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. Often the term point mutation also includes insertions or deletions of a single base pair...

 within exon
Exon
An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...

 11 of the LMNA gene.

Lamin A constitutes a major structural component of the lamina
Nuclear lamina
The nuclear lamina is a dense fibrillar network inside the nucleus of a eukaryotic cell. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division...

, a scaffold of proteins found inside the nuclear membrane of a cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

; progerin does not properly integrate into the lamina, which disrupts the scaffold structure and leads to significant disfigurement of the nucleus, characterized by a lobular shape. Researchers have shown that progerin activates genes that regulate stem cell
Stem cell
This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...

 differentiation
Cellular differentiation
In developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. Differentiation occurs numerous times during the development of a multicellular organism as the organism changes from a simple zygote to a complex system of...

 via the Notch signaling pathway.

Researchers are exploring farnesyltransferase inhibitor
Farnesyltransferase inhibitor
The farnesyltransferase inhibitors are a class of experimental cancer drugs that target protein farnesyltransferase with the downstream effect of preventing the proper functioning of the Ras , which is commonly abnormally active in cancer....

s as a potential pharmacological therapy against the negative effects of progerin on nuclear morphology.

Progerin, which has been linked to normal aging, is produced in healthy individuals via "sporadic use of the cryptic splice site".
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