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Nucleic Acid Structure

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...

Types of RNA

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...

Types of RNA

Types of RNA

Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...

Types of RNA

Types of RNA

Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...

Types of RNA

Types of RNA

Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...

MicroRNAs

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...

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Related Experiment Video

Updated: Jun 26, 2026

mirMachine: A One-Stop Shop for Plant miRNA Annotation

mirMachine: A One-Stop Shop for Plant miRNA Annotation

Published on: May 1, 2021

miR-21: a small multi-faceted RNA.

Anna M Krichevsky¹, Galina Gabriely

¹Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. akrichevsky@rics.bwh.harvard.edu

Journal of Cellular and Molecular Medicine

|January 30, 2009

Summary

MicroRNA-21 (miR-21) is a key regulator in human diseases, particularly cancer. This review summarizes its role in disease, focusing on its oncogenic functions and potential as a therapeutic target.

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mirMachine: A One-Stop Shop for Plant miRNA Annotation

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MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as a Novel Detection and Quantification Method

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Area of Science:

Molecular Biology
Genetics
Biochemistry

Background:

MicroRNAs (miRNAs) regulate gene expression, with over 1000 identified in humans.
Specific miRNAs, like miR-21, are crucial regulators in physiological and pathophysiological processes.
miR-21 is highly upregulated in glioblastoma and is extensively studied in oncology, stem cell biology, and aging.

Purpose of the Study:

To review the functions of miR-21 in human diseases, especially in oncology.
To highlight miR-21's regulatory mechanisms, oncogenic role, and mRNA targets in cancer.
To discuss miR-21's potential as a biomarker and therapeutic target in cancer treatment.

Main Methods:

Literature review of studies on miR-21.
Analysis of miR-21's role in various human diseases, with a focus on cancer.
Summary of experimental findings on miR-21 targets and functions.

Main Results:

miR-21 plays a significant role in the development and progression of various human cancers.
Identified targets of miR-21 include tumor suppressors and genes involved in cell proliferation and apoptosis.
miR-21 is implicated in regulating cell growth, survival, and metastasis in cancer.

Conclusions:

miR-21 is a critical oncomiR with diverse roles in cancer pathogenesis.
Understanding miR-21 regulation and function is essential for developing novel cancer diagnostics and therapeutics.
Targeting miR-21 presents a promising strategy for future cancer therapy.