The DNA consists of three or four tandem repeats that code for 31 amino acid long residues.
The gene contains 15 exons and has a size of 310064 base pairs. Alternative splicing of this gene gives rise to a large variety of transcripts and isoforms.

Four transcription variants have been characterized.
- MAP2 Isoform 5 (NM_001039538.1 --> NP_001034627.1): The difference in this isoform is characterized by the 5 UTR which results in the production of a longer protein when compared to isoform 2.
- MAP2 Isoform 1 (NM_002374.3 --> NP_002365.3): This isoform is thought to be the longest encoded and contains three alternative in-frame exons when compared to isoform 2. The tubulin binding and MAP2 projection domains are conserved.
- MAP2 Isoform 2 (NM_031845.2 --> NP_114033.2): This is the shortest transcript.
- MAP2 Isoform 4 (NM_031847.2 --> NP_114035.2): One alternate in-frame exon compared to isoform 2.

Variant 5	mRNA				Gene
	Exon	Start	End	Length	Start	End	Length
	1	1	230	230	1	230	230
	2	231	280	50	83546	83595	50
	3	281	345	65	155990	156054	65
	4	346	422	77	201007	201083	77
	5	423	713	291	229096	229386	291
	6	714	827	114	254526	254639	114
	7	828	905	78	256704	256781	78
	8	906	967	62	276231	276292	62
	9	968	1138	171	280404	280574	171
	10	1139	1286	148	281534	281681	148
	11	1287	1627	341	285868	286208	341
	12	1628	1720	93	299549	299641	93
	13	1721	1802	82*	301633	301744	112*
	14	1803	1915	113	305804	305916	113
	15	1916	5844	3929	306136	310064	3929
			TOTAL LENGTH : 5844*

Variant 1	mRNA				Gene
	Exon	Start	End	Length	Start	End	Length
	1	1	77	77	155633	155709	77
	2	78	142	65	155990	156054	65
	3	143	219	77	201007	201083	77
	4	220	510	291	229096	229386	291
	5	511	624	114	254526	254639	114
	6	625	702	78	256704	256781	78
	7	703	4428	3726	268579	272304	3726
	8	4429	4635	207	272496	272702	207
	9	4636	4770	135	272871	273005	135
	10	4771	4832	62	276231	276292	62
	11	4833	4980	148	281534	281681	148
	12	4981	5321	341	285868	286208	341
	13	5322	5403	82	301663	301744	82
	14	5404	5516	113	305804	305916	113
	15	5517	9445	3929	306136	310064	3929
			TOTAL LENGTH : 9445

Variant 4	mRNA				Gene
	Exon	Start	End	Length	Start	End	Length
	1	1	77	77	155633	155709	77
	2	78	142	65	155990	156054	65
	3	143	219	77	201007	201083	77
	4	220	510	291	229096	229386	291
	5	511	624	114	254526	254639	114
	6	625	702	78	256704	256781	78
	7	703	764	62	276231	276292	62
	8	765	912	148	281534	281681	148
	9	913	1253	341	285868	286208	341
	10	1254	1346	93	299549	299641	93
	11	1347	1428	82	301663	301744	82
	12	1429	1541	113	305804	305916	113
	13	1542	5470	3929	306136	310064	3929
			TOTAL LENGTH : 5470

Variant 2	mRNA				Gene
	Exon	Star	End	Length	Start	End	Length
	1	1	77	77	155633	155709	77
	2	78	142	65	155990	156054	65
	3	143	219	77	201007	201083	77
	4	220	510	291	229096	229386	291
	5	511	624	114	254526	254639	114
	6	625	702	78	256704	256781	78
	7	703	764	62	276231	276292	62
	8	765	912	148	281534	281681	148
	9	913	1253	341	285868	286208	341
	10	1254	1335	82	301663	301744	82
	11	1336	1448	113	305804	305916	113
	12	1449	5377	3929	306136	310064	3929
			TOTAL LENGTH : 5377

*There is a discrepancy between base pair numbers recorded for the transcript and the gene for this exon.

None.

MAP2 is an approximately 1827 amino acid long protein with an estimated molecular weight of 200 kDa, with the exact molecular weight varying by isoform. Four isoforms have been characterized, but additional ones are thought to exist. The protein undergoes post-translational phosphorylation upon DNA damage. The phosphorylation is hypothesized to be catalyzed by ATM or ATR. In the rat brain, the various isoforms were characterized at different stages of development - isoform MAP2B is found throughout rat brain development, while MAP2A appears towards the end of the second week of post-natal life. MAP2C is found during the early development of the brain, but after maturation is only found in the neural cells of the retina, olfactory bulb and the cerebellum.

MAP2 is a mostly unfolded protein that changes conformation upon binding to its target molecule. A domain near its carboxyl terminus enables MAP2 protein to bind to the microtubules. A 31 amino acid long repeating motif is characteristic of this protein. However, it is found that this motif is not sufficient by itself to bind to microtubules. Two contiguous sequences on either end of this repeating structure on both the amino and carboxyl ends enable the binding of this protein to the microtubules. A proline rich domain on the amino end is thought to be especially crucial in this process. The protein is known to have three tubulin binding domains spanning residues 1160-1691; 1692-1722; 1723-1754. The protein also has a projection domain which extends from residues 377-1505. All isoforms have a conserved C-terminal domain which contain tubulin binding repeats and a conserved N-terminal projection domain. The projection domain varies in size across isoforms, has a net negative charge and exerts a long range repulsive force. This gives a potential mechanism that explains how MAP2 regulates the spacing between microtubules.

MAP2 plays a major role in dendrite morphogenesis and is normally expressed in neurons. It has also been reported to be ectopically expressed in several cancers including melanoma and breast cancer.

MAP2 mRNAs were found in the avian neuronal cell body cytoplasm; however the protein was found localized to the dendrites in mammals (Cristofanilli et al., 2004). The same report shows that avian neuronal MAP2 mRNA lacks a dendritic targeting element in its 3 UTR. Local expression within dendrites is hypothesized to be more suited to regulate need based synthesis. Tubulin, a protein expressed in both axons and dendrites is known to be expressed in the cytoplasm of the cell body showing that location specific expression of proteins is important to the maintenance of polarity of the neural cells.

MAP2 stabilizes microtubule bundling and stiffening through the interactions of several weak binding sites to the microtubules on the protein. The strength of bundling of microtubules is directly correlated to the strength of the binding to MAP2. This enables the microtubules to support outgrowth from the cells. When MAP2 was expressed by transfection in non neuronal cells, it induced the rearrangement of the microtubules into long bundles. These bundles enabled outgrowths from the non neuronal cells. Experiments done with knockout mice show that the role of MAP2 in neuronal morphogenesis may be redundant (Teng et al., 2001). Single knockouts of MAP2 did not show any severe phenotypes but simultaneous knockouts of MAP2 and MAP1B died in the prenatal stage (Teng et al., 2001). There are several reports of functional redundancy amongst the MAP proteins.

A microtubule associated protein with similar function to MAP2 is known to be expressed in the rat (Rattus norvegicus), chicken (Gallus gallus) and lizard (Anolis carolinensis) with varying levels of sequence homology. In the fruit fly, the tau gene seems to perform a similar function.

35 SNPs associated with MAP2 have been identified. The CAGs, which are a set of trinucleotide sequences starting at exon 1 of the MAP2 gene on the 5 UTR region, are conserved in the general population (Kalcheva et al., 1999).