LARGEST HUMAN GENE AND ITS ENCODED PROTEIN
Today we’re going to talk about the “largest gene” in human body, but before that we must have a basic and brief concept about genes.
Genes are “basic physical and functional unit of heredity”. Genes make up the sequence of DNA (genotypes).
So we come to know, that genes are the fundamental units that pass out the heredity characteristics and traits (i,e hair color, skin tone, height, intelligence, etc.) to the next generation (during reproduction).Genes also encode and store the useful information about various processes taking place in human body ,for example: protein building.
In this scientifically developed era, genes are targeted to help mankind and upgrade facet of life.
TOTAL GENES (IN HUMAN BODY)
According to the scientists, there are 25,000 genes (approximately) in human body. Out of which 20,687 genes encode information about proteins (protein encoding genes).
The largest gene in human body is DMD. It consists of 2.4 Million Base Pairs and you will be astonished to know that it takes almost 16 hours to transcribe (first step of gene expression in which a particular DNA segment is copied into RNA).It comprises of 79 exons (DNA sequence and it encodes information about a protein called “dystrophin”.
Dystrophin is one of the very important proteins in our body because if we lack dystrophin, we’ll be no more able to move.
Let’s talk more about dystrophin.
It is rod shaped protein and connects the cytoskeleton of muscle fiber with extra-cellular matrix. Dystrophin is predominately present in Skeletal Muscles and Cardiac Muscles but a little amount is also present in Nerve Cells. In skeletal and cardiac muscles, dystrophin plays a vital role. It protects muscles fibers from any mishap (injury) by working in the form of a protein complex (dystrophin-complex).It also strengthens the muscle fibers by providing them massive support during contraction and relaxation. Dystrophin complex also links with proteins which send and receive chemical signals and hence plays a role in cell signaling as well.
In nerve cells, it is greatly responsible for the normal functioning of synapses (junction between two nerve cells where impulses pass by diffusion of neurotransmitters).
IF DYSTROPHINE is so important, what would happen if its deficiency occurs?
The deficiency in dystrophin can cause severe muscular weakness and our muscles lose their mobility and become stiff. A person suffering from its deficiency can become wheel-chaired. The deficiency of dystrophin is characterized as DUCHENNE MUSCULAR DYSTROPHY.
So this was a brief description of the largest human gene and its encoded protein. However it doesn’t covers all the aspects but I’m sure it will provide you with a basic knowledge facts about DMD.