The Diversity in RNA: mRNA, tRNA, miRNA, rRNA, and more!

When studying about RNA and DNA in elementary and middle school, I was always told that DNA was the more important between them. Hearing this over and over again throughout my educational career, it got ingrained into me: RNA wasn't that important of a biological molecule. It was secondary to DNA, it was the lesser important ribonucleic acid, it was an afterthough at best. However, an introductory AP Biology course in my freshman year of high school, some independent studying, and a little bit of research was quick to prove me wrong.

RNA, or ribonucleic acid (maybe this is another reason I thought DNA was more important -- RNA doesn't have the deoxy!) is a molecule found in every single living organism, just like DNA. RNA plays a crucial role in protein synthesis by carrying genetic information from DNA to the ribosomes, where it is translated into proteins. However, RNA is typically single-stranded (as opposed to our double-stranded DNA), and RNA contains the base uracil instead of thymine.

In this blog post, I'll be talking about mRNA, tRNA, and rRNA.

messengerRNA (mRNA), transferRNA (tRNA), and ribosomalRNA (rRNA) should excite those familiar with genomics. For those new to this field, get ready for an explanation on some of the coolest molecules mankind is aware of!

mRNA is kind of an intermediary. It's more of a "state" of RNA as opposed to a "type" of RNA. While DNA holds the genetic information for humans, mRNA is what converts instructions from DNA to proteins (which is what the body can actually ready and act upon). mRNA's role as a "messenger" is very important - without mRNA, we wouldn't have proteins, which are critical to sustaining life.

Beyond its biological role, mRNA has gained prominence in many facets of medicine, particularly in vaccine development. The success of traditional vaccines often relied on weak pathogens that couldn't fight back that warranted an immune response, but mRNA vaccines use synthetic mRNA sequences that instruct cells to produce specific viral cells. (For context, vaccines work by injecting a small portion of the viral we're trying to fight against into the body, such that the body is more prepared to fight any further cells of the viral because the immune system is activated). mRNA is able to accomplish the tasks of vaccines efficiently. mRNA was a significant area of study during COVID-19 and the successful distribution of vaccines.

The next kind of RNA I'll be discussing is transfer RNA, also known as tRNA. tRNA is like the Google Translate of genetic code. It takes the instructions written in messenger RNA (mRNA) and translates them into the amino acids that form proteins, which are essential for nearly every process in living organisms. What makes tRNA so fascinating is its adaptability: its anticodon region can match specific codons (group of three amino acids) on mRNA, while its other end attaches to a corresponding amino acid, ensuring the correct assembly of proteins.

The potential of tRNA extends beyond basic biology. In biotechnology and medicine, engineered tRNA molecules could revolutionize synthetic biology, enabling the production of entirely new proteins or therapeutic compounds. In disease treatment, tRNA-based therapies could address genetic disorders by bypassing mutations in mRNA, offering a new therapeutic solution for diseases previously thought to be untreatable.

Lastly, we have ribosomal RNA, which is an important addition in the protein synthesis process. rRNA forms the core structural components of ribosomes, which synthesize proteins. rRNA is important because without it, ribosomes wouldn't be able to function and thus couldn't create proteins. And rRNA isn't just a structural scaffold, it's a ribozyme, a type of RNA that catalyzes the chemical reactions that link amino acids to proteins.

Plus, the sequences of rRNA are "highly conserved" - meaning the nucleotide sequences are remarkably similar across various species. This is because natural selection has preserved these species, because they're so important. Since ribosomes and proteins are essential for all cells, rRNA is a target for amitbiotics that inhibit bacterial ribosomes without affecting human ribosomes. This selective targeting has been pivotal in treating bacterial infections.

Now, I've discussed mRNA, tRNA, and rRNA, and the fact that they also are relevant to the synthesis of proteins. But, why do proteins matter so much?

Proteins perform every single task required for cells and organisms to grow and function.

Proteins like collagen and keratin (yes, these proteins are the ones you see in Costco all the time) provide strength to tissues like skin, bones, and hair. Another comonly used word you might've heard is enzymes. Enzymes are proteins, and enzymes speed up chemical reactions in the body exponentially. Without them, processes like digestion and DNA replication would be far too slow to sustain life.

Hemoglobin is another protein that transports oxygen in the blood. Proteins like ferritin store essential molecules for every part of the body, such as iron.

Plus, all hormones are proteins! (Kind of a side note but I think https://training.seer.cancer.gov/anatomy/endocrine/hormones.html is an amazing source to check out. It goes into a lot of depth into hormones and the endocrine system but it's still concise. Really good source for anyone interested). We might not like the hormones that cause mood swings, but hormones such as insulin and other receptors cause cells to send and receive signals, coordinating processes like cell growth and immune responses.

Another major type of protein is an antibody: proteins that identify and neutralize harmful pathogens like bacteria and viruses, forming a key part inthe immune system. There's also motor proteins, like myosin and actin, which enable muscle contraction and even basic cellular movement such as the growth of organelles.

Proteins are essential not only for human health but also for life on Earth.

Proteins are the molecular machines that make life happen, from the cellular level to the organism level. Their importance can’t be overstated—they are quite literally life’s builders, movers, and operators!

The various types of RNA I mentioned are all directly related to helping proteins do their thing. I hope this blog post shed some light on DNA's ignored sibling RNA, and introduced the significance of RNA and proteins.