c-Myc| gene and protein structures| function| mutation

Table of content

• What is c-myc Gene Family 
• c-myc
• Structure of c-myc gene and protein  
• Mechanism of c-MYC Ativation
• Function of c-myc Gene

What is c-myc Gene Family 

MYC is a family of regulator gene and proto-oncogene that encode a protein which regulate the expression of other gene in an estimation it regulate nearly 15 % the expression of other gene and basically involved in cell   proliferation, cell growth, apoptosis and cell transformation. Infect they determine the fate of a cell. MYC gene family include other member like c-Myc (c-MYC), l-Myc (I-MYC), and n-Myc  (n-MYC). C-Myc is firstly discovered and referred as MYC.

c-myc

c-myc was discovered in human Burkitt's lymphoma, which show homologue to viral oncogene v-Myc which was isolated from an avian retrovirus. c-myc gene is located at chromosome no 8 at position 8q24.21, which encode the c-myc protein with in the nucleus which regulate the expression of other gene, in two ways.

• Firstly, these proteins act as transcription factors for other gene.
• Secondly these proteins act as histone modifier which help in transcription of a gene.

The encoded protein implicated in various cellular process like cell growth, proliferation, loss of differentiation and apoptosis.

Structure of c-myc gene and protein 

The structure of c-myc gene consist of three exons and two introns, more over the c-Myc transcription is regulated by multiple promoters. 

Figure 1: represents the structure and location of c-myc gene.

c-Myc protein is a 65 kDa nuclear phosphoro-protein, the basic structure of the protein consists of basic helix-loop-helix domain and leucine zipper (bHLH/LZ), bHLH is a DNA binding domain while LZ is bind with other protein (MAX).

Figure 3: represents secondary c-Myc protein structure.

Mechanism of c-MYC Ativation

The function of c-MYC is mediated by another protein that is Max, c-MYC when binds to the Max and generated a complex called Myc-Max complexes. This Myc-Max complexes releases the different type of transcription factors which regulate the expression of other gene that involve in cell proliferation, growth, apoptosis etc. Similarly, this Myc-Max complexes mechanism is controlled and inhibit by other factors to regulate the process.

Figure 3: represents Myc-Max complexe and their binding to DNA.

Function of c-myc Gene

c- myc gene involve in many function

• The primary functions of c-Myc are to promote cell proliferation and to arrest cell differentiation
• Have role in the regulation of stem cell function. With the cooperation of n-Myc, c-Myc inhibits the differentiation of stem cells, such as embryonic stem cells 
• c-Myc is not only an inducer of cell proliferation, but also has the ability to regulate cell apoptosis via various signaling pathways.
• Many observations suggested that protein synthesis is regulated by c-Myc in multiple ways, in which the transcription of various RNA, iRNA, and ribosomes is controlled by the oncogene product.
• Recently, evidence has been accumulating that c-Myc also regulates the expression of miRNAs, which are a set of small, non-protein-coding RNAs and regulate gene expression at the post-transcriptional level.