The aim of the website is...

to give an in depth knowledge of what happens to secreted proteins after translation, for readers to understand the pathway all the way from the synthesis to the secretion.

This page includes a brief summary of firstly how proteins are made and the pathways it can take. We have split the process into 5 main parts such as-

A secretory protein is defined as a protein that is actively secreted out of the cell. Secretory proteins play a very important role in cellular communication, both intracellularly and extracellularly. It is estimated that 9% of the human proteome are secretory proteins, most commonly expressed in endocrine cells and lymphocytes, however secretory pathways are present in all cells in order to communicate intracellularly. The secretory pathway is composed of the er golgi then through the plasma membrane. In order for secretory proteins to be targeted to the ER they must encode a sequence peptide, which acts as a molecular tag, which enables the said protein to be recognised by chaperones that escort the protein to the er. The signal peptide is encoded in the dna before transcription takes place, hence the coding sequence for secreted proteins is essential the ability of the proteins to be taken to their specific location. Signal peptide for secreted proteins encode a polar, uncharged region at the c terminus and a short (15-30 amino acids), positive, hydrophobic a helix at the n terminus of the protein. The n terminus is inserted into the er to tether it there then once it is within the er lumen, the sp is cleaved from the rest of the protein.

It is important for signalling proteins secreted to undergo the correct amount of methylation etc to protect them from the harsher conditions outside the cell in order to remain undamged until reached the designated site for action.

                Introduction

Background into the synthesis.. 

Although the main focus of the website is to understand what happens to protein after translation. It is essential for an understanding of translation. If unaware of what translation is overall just have a simple search if still no luck or ask any questions!

 Research by recent scientists has concluded that the human body contains approximately 37.2 trillion cells on average! And each of those cells contains millions of proteins. Proteins are key molecular building blocks for all organism.

What are proteins?

Proteins are large biomolecules, or macromolecules which consist of one or more long chains of amino acid residues. They have a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells, and organisms, and transporting molecules from one location to another.

How are these proteins made?

A gene is used to build a protein within two main steps known as transcription and translation.

 Transcription! 

This is the first step of protein production, where DNA sequences of genes are rewritten into RNA. In eukaryotes, the RNA is processed to make the final product messenger RNA (mRNA).

Translation!

The second step of protein production, is when mRNA is "decoded" by ribosomes to build a protein that contains a specific series of amino acids joined by peptide bonds.  

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