What is the Difference Between NeuN and MAP2

The key difference between NeuN and MAP2 is that NeuN is a protein coded by the RBFOX3 gene, while MAP2 is a protein coded by the MAP2 gene.

Neuronal markers are useful for neuronal identification. They are often essential in distinguishing neurons from other brain cells, determining neuronal identity, defining a neuron’s function, and establishing synaptic partners. There are several neuronal markers, such as immature neuronal markers (NCAM), mature neuronal markers (NeuN, MAP2, beta-III tubulin), functional neuronal markers, (ChAT, tyrosine hydroxylase), and synaptic neuronal markers (PSD-95, synaptophysin).

CONTENTS

1. Overview and Key Difference
2. What is NeuN 
3. What is MAP2
4. Similarities – NeuN and MAP2
5. NeuN vs MAP2 in Tabular Form
6. Summary – NeuN vs MAP2

What is NeuN?

NeuN is a protein encoded by the RBFOX3 gene that is commonly used as a neuronal biomarker. NeuN or RBFOX3 is one of the three mammalian members of the RNA binding protein of the RBFOX gene family. All proteins of the RBFOX gene family are involved in the regulation of alternative RNA splicing. Originally, it was identified as an epitope NeuN that is located within the N terminal region of the RBFOX3 protein. RBFOX family members are highly conserved, having a single RNA recognition motif (RRM) type RNA binding domain (RBD) near the centre of the protein sequence. RBFOX3 protein is highly conserved across humans, mice, and rats. This protein participates in the regulation of alternative splicing between family members as well as in autoregulation. The brain and muscle-specific targets for alternative splicing are well established for RBFOX proteins.

The expression of NeuN/ RBFOX3 protein is restricted to the nervous system and has widely been used in stroke research. Therefore, it is recognized as a marker of mature neuronal cell types in the spinal cord, cerebral cortex, hippocampus, dorsal thalamus, caudate/putamen, and cerebellum. NeuN protein can be detected using RBFOX3/NeuN antibody through immunoreactivity. NeuN is a protein that is a homologue to the protein product of a sex-determining gene in Caenorhabditis elegans.

What is MAP2?

Microtubule-associated protein 2 or MAP2 is a protein used as a mature neuronal marker. The gene MAP2 codes for this protein. MAP2 belongs to MAP2/Tau family. It has four isoforms as MAP2a, MAP2b, MAP2c, and MAP2d. MAP2 isoforms are associated with microtubules and mediate their interaction with actin filaments, thereby playing a critical function in organizing the microtubule-actin network. Furthermore, MAP2 isoforms are developmentally regulated and differentially expressed in neurons and some glial cells.

MAP2c is expressed in the developing brain, and other isoforms are expressed in the adult brain. The distribution of MAP2 isoforms also varies. MAP2a and MAP2b are localized to dendrites, while MAP2c is found in axons. The expression of MAP2d is not limited to neurons and can also be found in glia, such as oligodendrocytes. MAP2 is recognized as a useful marker of mature neuronal cells and can be detected by MAP2 antibodies through immunoreactivity.

What are the Similarities Between NeuN and MAP2?

• NeuN and MAP2 are two mature neuronal markers.
• Both are proteins made up of amino acids.
• They are expressed in mature neuronal cells.
• Both proteins can be detected through specific antibodies through immunoreactivity.
• They carry out very important functions in the body.

What is the Difference Between NeuN and MAP2?

NeuN is a protein coded by the RBFOX3 gene, while MAP2 is a protein coded by the MAP2 gene. Thus, this is the key difference between NeuN and MAP2. Furthermore, the molecular weight of NeuN is 46 kDa, while the molecular weight of MAP2 is 199 kDa.

The below infographic presents the differences between NeuN and MAP2 in tabular form for side by side comparison.

Summary – NeuN vs MAP2

Neuronal markers are useful for the identification of neuronal cells. NeuN and MAP2 are two mature neuronal markers. NeuN is a protein encoded by the RBFOX3 gene, while MAP2 is a protein encoded by the MAP2 gene. So, this is the key difference between NeuN and MAP2.

Reference:

1. Gusel’nikova, V V, and D E Korzhevskiy. “Neun as a Neuronal Nuclear Antigen and Neuron Differentiation Marker.” Acta Naturae, A.I. Gordeyev, 2015.
2. “MAP2 Microtubule Associated Protein 2 [Homo Sapiens (Human)] – Gene – NCBI.” National Center for Biotechnology Information, U.S. National Library of Medicine.

Image Courtesy:

1. “Rat hippocampus stained with antibody to NeuN (green), myelin basic protein (red) and DNA (blue)” By GerryShaw – Using a confocal microscope and fluoresent antibody staining Previously published: 2015-11-10 (CC BY-SA 3.0) via Commons Wikimedia
2. “MAP2-tau in neurons” By GerryShaw – Own work (CC BY-SA 4.0) via Commons Wikimedia