What Is Lamin A Protein

Over the past few months we have received numerous questions concerning a popular christian icon the protein laminin.

What is lamin a protein.

Lamin a consists of a central rod domain flanked by hydrophobic n and c terminal domains. Lamin a is targeted to the nuclear membrane by an isoprenyl group but it is cleaved shortly after arriving at the membrane. Its initial form called prelamin a undergoes a complex series of steps that are necessary for the protein to be inserted into the lamina. The lamins are the major architectural proteins of the animal cell nucleus.

It stays associated with the membrane through protein protein interactions of itself and other membrane associated proteins such as lap1. The lamin a protein must be processed within the cell before becoming part of the lamina. In this case lamin a may be dialyzed into tris hepes or napi buffers with ph 8 0 8 5 and containing 250 mm nacl and 1 mm dtt in which most of the lamin protein should stay soluble at concentrations below 50 μg ml for several hours. Hutchinson gilford progeria syndrome hgps omim 176670 is a rare disorder characterized by accelerated aging and early death frequently from stroke or coronary artery disease.

At ph and salt concentrations below this or at higher protein concentrations lamin a will tend to oligomerize. Depolymerization of the nuclear lamins leads to disintegration of the nuclear envelope. After farnesylation at the caax box motif. Lamin proteins are involved in the disassembling and reforming of the nuclear envelope during mitosis the positioning of nuclear pores and programmed cell death.

Mutations in lamin genes can result in several genetic laminopathies which may be life threatening. Lamin a is a 664 amino acid protein with a molecular weight of 70 kda calculated 74 139 da and a pi of 7 0 theoretical pi 7 4. It is an essential scaffolding supporting component of the nuclear envelope which is the membrane that surrounds the nucleus. Laminin interestingly is in the shape of a cross see here in fact a quick internet search turns up multiple websites selling t shirts mousepads stickers coffee mugs and a host of other items with a picture of the laminin protein.

Lamin c does not have to undergo this processing before becoming part of the lamina. Lamins line the inside of the nuclear membrane where they provide a platform for the binding of proteins and chromatin and confer mechanical stability. This protein plays an important role in determining the shape of the nucleus within cells. 90 of hgps cases carry the lmna g608g ggc ggt mutation within exon 11 of lmna activating a splice donor site that results in production of a dominant negative form of lamin a protein denoted progerin.

The lamin a protein must be processed within the cell before becoming part of the lamina. Lamin c does not have to undergo this processing before becoming part of the lamina.