kalyani rajalingham maoa
TRANSCRIPT
Molecular Characterization of monoamine oxidase A
1 ABSTRACT
The MAO-A gene – involved in the degradation of amine neurotransmitters - is one that is associated with violent tendencies, aggressive behaviour, and low intelligence. Low expression levels are usually yoked to the said tendencies. In this study, I try to characterize the MAO-A gene via a bioinformatics analysis. Analysis shows that sites 374, and 406 in the human MAO-A were conserved in 106 sequences; however, mutations in sites 374, and 406 results in the complete loss of activity of the protein. Natural variant sites 15, 188, 314, and 520 were not found to be conserved in all 106 organisms; however, amongst the PhyTrels, sites 188, 314, and 520 were found to be conserved. Further, gene, and protein expression levels were not found to be linearly correlated in Homo sapiens; protein levels of MAO-A was found to be high in most tissue. Gene expression of MAO-A was found to vary between organisms.
INTRODUCTION
The MAO-A gene is one that is associated with antisocial behaviour, and aggression (Hunter 2010,
Bortolato et al. 2012); antisocial tendencies, and MAO-A expression in the brain were found to be
inversely correlated (Bortolato et al. 2012). Located on the X chromosome (Xp11.3), the MAO-A gene
has been linked to a number of diseases; in particular, a nonsense mutation in the MAO-A gene, in
humans, has been linked to Brunner’s syndrome, a form of mental retardation. Low levels of MAO-A in
Brunner’s Syndrome results in an increased level of amine neurotransmitters which is accompanied by
particular behavioural tendencies – hypersexuality, sleep disorder, mood swings, and violent tendencies
(Hunter 2010). Moreover, Brunner syndrome is associated with violence, antisocial behaviour (ex: rape,
murder, exhibitionism, voyeurism, arson) usually as a result of minor stresses (Bortolato and Shih 2011).
Brunner’s syndrome, however, is very rare – low frequency. There exists two MAO genes in humans –
MAOA, and MAOB; with 70% sequence similarity, loss of both MAO genes would result in severe mental
retardation (Cases et al. 2010). MAO-A, an enzyme in the mitochondrion (Cases et al. 2010), is involved
in the degradation of various amine neurotransmitters (ex: dopamine, serotonin, and norepinephrine)
(Bortolato et al. 2012). Inhibitors of MAO, usually targeting MAO-A, have antidepressant properties –
which results in an increase in the synaptic concentrations of 5-HT, and modifies neuronal firing rates
(Bortolato and Shih 2011). One variant - responsible for low expression of MAOA - with a frequency of
Molecular Characterization of monoamine oxidase A
2 40% in the general population is also known as MAOA-L (Hunter 2010). MRI data shows that
individuals with MAOA-L have a small limbic system which is involved in emotion, behaviour, and
memory; individuals with MAOA-L had a poor impulse control (Hunter 2010). However, Hunter (2010)
notes that individuals who possess the MAOA-L variant require a “trigger” to induce the violent
tendencies. Amongst the number of diseases that is associated with MAO-A are sociopathy, antisocial
personality disorder, and psychopathy. Many have wondered about the link between MAO-A, and many a
disease. In this paper, I seek to analyze the MAO-A protein, to characterize both function, and structure as
well as determine whether expression in animals is similar to humans.
RESULTS
DOMAINS, MOTIFS, INTERACTIONS AND PATHWAYS
Located on the outer membrane of the mitochondrion, this integral membrane protein functions in
synaptic transmission, and metabolic processes (Supplementary Figure S1); MAO-A is an oxidoreductase.
The MAO-A gene was found to be associated with an Amine oxidase domain (IPR002937), which
possesses oxidoreductase activity, and belongs to the flavin amine oxidase family (IPR001613)
(Supplementary Figure S2). MAO-A requires FAD as a cofactor, and was found to interact with ALDH2,
CYP2C19, SLC6A4, COMT, DRD4, DBH, DDC, PNMT, CYP2C9, and AOX1. MAO-A is involved
in the degradation of the following compounds: dopamine, melatonin, putrescine, serotonin, tryptophan,
noradrenaline and adrenaline; it is also involved in the biosynthesis of isoquinoline alkaloids, secondary
metabolites, and salidroside. MAO-A is involved in the metabolism of the following compounds: glycine,
serine, threonine, arginine, proline, tyrosine, histidine, phenylalanine, tryptophan, and drugs. It has also
been implicated in cocaine, and amphetamine addiction as well as alcoholism. MAO-A targets the
dopaminergic, and sertonergic synapses, and thus targets the nervous system.
Molecular Characterization of monoamine oxidase A
3 STRUCTURAL ANALYSIS
The MAO-A gene – 527 amino acids in length - has two important sites: site 335, and site 374. The
cytoplasmic region spans amino acids 1 to 497; the mitochondrial membrane region spans amino acids 519
to 627; the transmembrane region spans amino acids 498 to 518. Site 335 is responsible for substrate
specificity, and site 374 is required for catalytic activity. Mutations at sites 374, and 406 results in the
complete loss of activity of the protein (Supplementary Figure S2). Natural variants of MAO-A include
the following: site 15 from D to E (s15-DE), s188-EK, s314-FV, and s520-KR.
PHYLOGENETIC ANALYSIS
Figure 1: Molecular phylogenetic analysis by Maximum Likelihood method for the MAOA gene. A Maximum Likelihood tree was constructed (JTT model, Gamma distribution (5 categories, +G, parameter = 0.5703), Bootstrap (50)). The tree shows branches with bootstrap values greater than 70. [MAO-A= Monoamine oxidases A; MAO-B= Monoamine oxidases B; MAO-A I = isoform 1; MAO-A 2=isoform 2; MAO-A K where K is a variant; unrooted tree] Phylogenetic analyses were performed in MEGA6.
Both isoforms of the MAO-A gene in Homo sapiens were found to be similar to the MAO-A gene present
in Pan paniscus, Pan troglodytes, Nomascus leucogenys, Gorilla gorilla gorilla, Pongo abelii, Macaca
mulatta, Chlorocebus_sabaeus, and Papio Anubis – this group will be referred to as the PhyTrel (Figure
1). Conserved sites were observed between amino acid 174, and 497 of the Homo sapiens MAO-A I in all
106 sequences. In particular, two stretches of conserved sites are noteworthy; the first gapped stretch of
conserved sites was observed between amino acids 174, and 258 of the Homo sapiens MAO-A gene, and
Molecular Characterization of monoamine oxidase A
4 the second gapped stretch was observed between amino acids 386 to 452 in the Homo sapiens
(Supplementary Figure S4). Mapping this region onto the MAO-A I Homo sapiens gene, it falls into the
Amino oxidase domain. In particular, although site 335 (of the Homo sapiens MAO-A) was not found to
be conserved in all 106 sequences, sites 374, and 406 were found to be conserved in all 106 sequences.
Sites 15, 188, 314, and 520 were not found to be conserved in all 106 organisms. Amongst the PhyTrels,
sites 188, 314, and 520 were found to be conserved (Supplementary Table S1).
COMPARING GENE EXPRESSION OF MAO-A IN ORGANISMS
Gene Expression
The EST profile of the MAO-A gene in Homo sapiens
shows high levels of gene expression in the bladder, the
PNS, the placenta, the prostate, the small intestine, and
soft tissue; non-zero gene expression levels were observed
in the bone, the bone marrow, the brain, the colon, the
eye, the heart, the kidney, liver, lung, muscle, ovary,
pancreas, skin, testis, and uterus (Supplementary Figure
S5). Differential gene expression was observed between
organisms (Figure 3). For instance, relative gene
expression of MAO-A in the kidney was low in
Monodelphis domestica, Gallus gallus, and Bos Taurus,
and high in Xenopus tropicalis, and Anolis carolinensis. In another instance, gene expression was found to
be low in the heart of Xenopus tropicalis, Monodelphis domestica, Gallus gallus, and Bos Taurus; in
Anolis carolinensis, however, expression is high in the heart.
Molecular Characterization of monoamine oxidase A
5
Figure 3: Gene expression of MAO-A in various tissues. [Information gathered from the Expression Atlas; A= Bos Taurus; B= Anolis carolinensis; C= Gallus gallus; D=Monodelphis domestica; E= Xenopus tropicalis] Protein Expression
Gene expression, and protein expression were not linearly
correlated (Figure 4). Oddly enough, the MAO-A protein was
found to be absent only in the lateral ventricle, hippocampus,
lymph node, and bone marrow. Protein levels are quite high in
most tissue (of Homo sapiens) – heart muscle, lung, endocrine
glands, tonsil, skin, and soft tissues, the reproductive system, the
urinary system, the digestive system, as well as the liver, the
gallbladder, and the pancreas. Further, a protein expression
analysis showed that for most cancers, the cancer staining level of
MAO-A did not differ from the normal level (Figure 5).
However, in some tissues, the expression of MAO-A was either
Molecular Characterization of monoamine oxidase A
6 higher or lower than the normal level.
Figure 5: Protein expression of MAO-A in cancer cells. (Source – Protein Atlas; The cancer staining bar represents 12 replicates in total, wherein we observe low, medium, or high protein expression levels.)
DISCUSSION
The MAO-A gene has been linked to a number of functional breakdowns that are known to occur in
humans which in particular results in psychiatric and neurological problems; lack of MAO-A proteins
primarily affects the central nervous system. In this particular study, a bioinformatics analysis of the MAO-
A gene was conducted in an attempt to characterize the protein. Results show that a few sites are conserved
amongst 106 organisms. Amongst the conserved sites were sites 374, and 406 – mutations at this site
would result in the complete loss of function of MAO-A. Sites 188, 314, and 520 – natural variants in
humans - were found to be conserved in the PhyTrels (primates). Lack of MAO-A proteins primarily
affects the central nervous system; serotonin, dopamine, and norepinephrine. Further, concentrations of
MAO-A knockout mice were found to be elevated; adult MAO-A knockout mice displayed aggressive
behaviours; MAO-A-/- mice (Tg8) showed altered behaviours that could be reversed by supplying the
mouse with an inhibitor (acts like MAO-A) (Cases et al. 2010). In this particular paper, I found that
MAO-A expression was different between organisms. MAO-A levels were found to be higher in the brain
of Anolis carolinesis, and very low in that of Xenopus tropicalis. Dopamine, for instance, controls
movement, memory, alertness, attention, emotions, pleasure, and pain; high levels of dopamine results in
Molecular Characterization of monoamine oxidase A
7 impulsive behaviour, and paranoia. One must ask whether we can assess behaviour of a number of animals
based on similarity of the MAO-A gene, and expression profiles.
METHODS
BLAST, and Phylogenetic Analysis. The protein sequence of MAO-A for Homo sapiens was
acquired at NCBI (http://www.ncbi.nlm.nih.gov/; NP_000231.1, NP_001257387.1). Two isoforms
were present; for the purposes of this paper, isoform variant 1 was selected (NP_000231.1). BLASTp
(protein BLAST, refseq_proteins, BLOSUM62 matrix, gap opening= 11, gap extention=1) was
performed using the protein sequence of isoform 1; output was downloaded in FASTA format. These
sequences were complemented with the protein sequences of orthologs that were obtained from the
Ortholog from Annotation Pipeline list, and HomoloGene at NCBI. MUSCLE was used to perform a
multiple sequence alignment (MEGA6.06, Gap opening penalty -2.9, Gap extending penalty 0,
Hydrophobicity multiplier 1.2, UPGMB clustering method). Phylogenic reconstruction was carried out
using the Maximum-likelihood method (MEGA6.06, bootstrap method 50, Jones-Taylor-Thornton
(JTT) model, Gamma distribution (G) 5, Nearest-Neighbour-Interchange (NNI)). No out-group was
used.
Domains, Motifs, and Interactions. To determine the domains, and motifs present, the SMART
(http://smart.embl-heidelberg.de/) database was accessed. InterPro (http://www.ebi.ac.uk/interpro/)
was used to confirm domains, and assess function of said domain. STING (http://string-db.org/) was
used to determine the partners of MAO-A (proteins with which it interacts).
Pathways. KEGG (http://www.genome.jp/kegg/) was accessed to determine pathway
information. ExPASy Enzyme (enzyme.expasy.or/), and BRENDA (http://www.brenda-enzymes.info/)
were accessed for information about the enzyme. UniPROT (www.uniprot.org/) was used to access
information about mutagenesis.
Molecular Characterization of monoamine oxidase A
8 Comparing Gene Expression of MAO-A in organisms. UniGene
(http://www.ncbi.nlm.nih.gov/unigene) was accessed to retrieve EST profiles of MAO-A for a number of
species. Further, the Expression Atlas
(http://www.ebi.ac.uk/gxa/home;jsessionid=6116099BA8CB7DCA2F73E3843432C153) was also
accessed to collect gene expression profiles (for comparison). The Protein Atlas
(www.phosphosite.org/proteinAction.do?id=1911538&showAllSites=true) was used to determine levels
of MAO-A protein in various tissues.
REFERENCES Hunter, P. (2010). The psycho gene. EMBO Rep, 11(9), pp.667-669. Bortolato, M., Godar, S., Melis, M., Soggiu, A., Roncada, P., Casu, A., Flore, G., Chen, K., Frau, R., Urbani, A., Castelli, M., Devoto, P. and Shih, J. (2012). NMDARs Mediate the Role of Monoamine Oxidase A in Pathological Aggression. Journal of Neuroscience, 32(25), pp.8574-8582. Bortolato, M. and Shih, J. (2014). Behavioral outcomes of monoamine oxidase deficiency: Preclinical and clinical evidence. International Review of Neurobiology, 100(2011), pp.13-42. Cases, O., Seif, I., Grimsby, J., Gaspar, P., Chen, K., Pournin, S., Muller, U., Aguet, M., Babinet, C., Shih, J. and et, a. (1995). Aggressive behavior and altered amounts of brain serotonin and norepinephrine in mice lacking MAOA. Science, 268(5218), pp.1763-1766.
Molecular Characterization of monoamine oxidase A
9 SUPPLEMENTARY MATERIAL
Figure S1: Reaction catalyzed by MAO-A. [Source – BRENDA]
Molecular Characterization of monoamine oxidase A
10
Figure S2: Secondary, and 3D structure of MAO-A [Structures were obtained from the PDB]
Molecular Characterization of monoamine oxidase A
11 Table S1: List of MAO-A sequences used for phylogenetic analysis.
>gi|4557735|ref|NP_000231.1| amine oxidase [flavin-containing] A isoform 1 [Homo sapiens] >gi|332860606|ref|XP_003317484.1| PREDICTED: amine oxidase [flavin-containing] A-like [Pan troglodytes] >gi|55741561|ref|NP_001002969.1| amine oxidase [flavin-containing] A [Canis lupus familiaris] >gi|114326284|ref|NP_851357.2| amine oxidase [flavin-containing] A [Bos taurus] >gi|255759902|ref|NP_776101.3| amine oxidase [flavin-containing] A [Mus musculus] >gi|270288740|ref|NP_387502.1| amine oxidase [flavin-containing] A [Rattus norvegicus] >gi|512821168|ref|XP_002932844.2| PREDICTED: amine oxidase [flavin-containing] A-like isoform X1 [Xenopus (Silurana) tropicalis] >gi|395132504|ref|NP_001257387.1| amine oxidase [flavin-containing] A isoform 2 [Homo sapiens] >gi|297303663|ref|XP_001096840.2| PREDICTED: amine oxidase [flavin-containing] A [Macaca mulatta] >gi|719756952|ref|XP_010215009.1| PREDICTED: amine oxidase [flavin-containing] A [Tinamus guttatus] >gi|410988387|ref|XP_004000467.1| PREDICTED: amine oxidase [flavin-containing] A [Felis catus] >gi|71895251|ref|NP_001025970.1| monoamine oxidase A [Gallus gallus] >gi|674034908|ref|XP_008841403.1| PREDICTED: amine oxidase [flavin-containing] A [Nannospalax galili] >gi|584069823|ref|XP_006755251.1| PREDICTED: amine oxidase [flavin-containing] A [Myotis davidii] >gi|555958932|ref|XP_005891579.1| PREDICTED: amine oxidase [flavin-containing] A [Bos mutus] >gi|704179704|ref|XP_010134921.1| PREDICTED: amine oxidase [flavin-containing] A, partial [Buceros rhinoceros silvestris] >gi|700322686|ref|XP_009927895.1| PREDICTED: amine oxidase [flavin-containing] A [Haliaeetus albicilla] >gi|675624372|ref|XP_008940411.1| PREDICTED: LOW QUALITY PROTEIN: amine oxidase [flavin-containing] A [Merops nubicus] >gi|667309052|ref|XP_008583930.1| PREDICTED: amine oxidase [flavin-containing] A [Galeopterus variegatus] >gi|664771491|ref|XP_008504928.1| PREDICTED: amine oxidase [flavin-containing] A [Equus przewalskii] >gi|663281319|ref|XP_008498559.1| PREDICTED: amine oxidase [flavin-containing] A [Calypte anna] >gi|641722897|ref|XP_008151246.1| PREDICTED: amine oxidase [flavin-containing] A [Eptesicus fuscus] >gi|640776697|ref|XP_008052177.1| PREDICTED: amine oxidase [flavin-containing] A [Tarsius syrichta] >gi|426395651|ref|XP_004064079.1| PREDICTED: amine oxidase [flavin-containing] A isoform 1 [Gorilla gorilla gorilla] >gi|197099200|ref|NP_001124913.1| amine oxidase [flavin-containing] A [Pongo abelii] >gi|694984598|ref|XP_003317484.2| PREDICTED: amine oxidase [flavin-containing] A [Pan
Molecular Characterization of monoamine oxidase A
12 troglodytes] >gi|332243814|ref|XP_003271068.1| PREDICTED: amine oxidase [flavin-containing] A isoform 1 [Nomascus leucogenys] >gi|685621052|ref|XP_003919084.2| PREDICTED: amine oxidase [flavin-containing] A [Papio anubis] >gi|635143113|ref|XP_007989644.1| PREDICTED: amine oxidase [flavin-containing] A [Chlorocebus sabaeus] >gi|403297577|ref|XP_003939638.1| PREDICTED: amine oxidase [flavin-containing] A [Saimiri boliviensis boliviensis] >gi|395857318|ref|XP_003801045.1| PREDICTED: amine oxidase [flavin-containing] A-like [Otolemur garnettii] >gi|675766444|ref|XP_002762857.2| PREDICTED: amine oxidase [flavin-containing] A [Callithrix jacchus] >gi|511974496|ref|XP_004805214.1| PREDICTED: uncharacterized protein LOC101673386 [Mustela putorius furo] >gi|511866964|ref|XP_004754983.1| PREDICTED: uncharacterized protein LOC101673386 [Mustela putorius furo] >gi|671032262|ref|XP_008706937.1| PREDICTED: amine oxidase [flavin-containing] A [Ursus maritimus] >gi|591316143|ref|XP_007084416.1| PREDICTED: amine oxidase [flavin-containing] A [Panthera tigris altaica] >gi|126352690|ref|NP_001075301.1| amine oxidase [flavin-containing] A [Equus caballus] >gi|344292703|ref|XP_003418065.1| PREDICTED: amine oxidase [flavin-containing] A-like [Loxodonta africana] >gi|478521726|ref|XP_004435072.1| PREDICTED: amine oxidase [flavin-containing] A isoform 1 [Ceratotherium simum simum] >gi|478521728|ref|XP_004435073.1| PREDICTED: amine oxidase [flavin-containing] A isoform 2 [Ceratotherium simum simum] >gi|593711059|ref|XP_007102094.1| PREDICTED: amine oxidase [flavin-containing] A [Physeter catodon] >gi|625217725|ref|XP_003510347.2| PREDICTED: amine oxidase [flavin-containing] A isoform X1 [Cricetulus griseus] >gi|472384186|ref|XP_004411465.1| PREDICTED: amine oxidase [flavin-containing] A isoform 1 [Odobenus rosmarus divergens] >gi|466076048|ref|XP_004283458.1| PREDICTED: amine oxidase [flavin-containing] A isoform 1 [Orcinus orca] >gi|301775051|ref|XP_002922945.1| PREDICTED: amine oxidase [flavin-containing] A-like [Ailuropoda melanoleuca] >gi|532035608|ref|XP_005360700.1| PREDICTED: amine oxidase [flavin-containing] A [Microtus ochrogaster] >gi|602689629|ref|XP_007457032.1| PREDICTED: amine oxidase [flavin-containing] A [Lipotes vexillifer] >gi|560982464|ref|XP_006213459.1| PREDICTED: amine oxidase [flavin-containing] A [Vicugna pacos] >gi|594050885|ref|XP_006049784.1| PREDICTED: amine oxidase [flavin-containing] A [Bubalus bubalis] >gi|585168648|ref|XP_006736388.1| PREDICTED: amine oxidase [flavin-containing] A
Molecular Characterization of monoamine oxidase A
13 [Leptonychotes weddellii] >gi|533192469|ref|XP_005409056.1| PREDICTED: amine oxidase [flavin-containing] A [Chinchilla lanigera] >gi|532076495|ref|XP_005324039.1| PREDICTED: amine oxidase [flavin-containing] A [Ictidomys tridecemlineatus] >gi|594664370|ref|XP_007180326.1| PREDICTED: amine oxidase [flavin-containing] A [Balaenoptera acutorostrata scammoni] >gi|562839527|ref|XP_006148928.1| PREDICTED: amine oxidase [flavin-containing] A [Tupaia chinensis] >gi|48675943|ref|NP_001001640.1| amine oxidase [flavin-containing] A [Sus scrofa] >gi|655875522|ref|XP_008270740.1| PREDICTED: amine oxidase [flavin-containing] A [Oryctolagus cuniculus] >gi|507969399|ref|XP_004690018.1| PREDICTED: amine oxidase [flavin-containing] A [Condylura cristata] >gi|556728852|ref|XP_005960154.1| PREDICTED: amine oxidase [flavin-containing] A [Pantholops hodgsonii] >gi|589928229|ref|XP_006976937.1| PREDICTED: amine oxidase [flavin-containing] A [Peromyscus maniculatus bairdii] >gi|675766440|ref|XP_008987423.1| PREDICTED: amine oxidase [flavin-containing] A-like [Callithrix jacchus] >gi|426256882|ref|XP_004022065.1| PREDICTED: amine oxidase [flavin-containing] A [Ovis aries] >gi|548531575|ref|XP_005700962.1| PREDICTED: amine oxidase [flavin-containing] A [Capra hircus] >gi|471378424|ref|XP_004377014.1| PREDICTED: amine oxidase [flavin-containing] A [Trichechus manatus latirostris] >gi|507704679|ref|XP_004645373.1| PREDICTED: amine oxidase [flavin-containing] A-like [Octodon degus] >gi|507564285|ref|XP_004665815.1| PREDICTED: amine oxidase [flavin-containing] A [Jaculus jaculus] >gi|512975964|ref|XP_004850052.1| PREDICTED: amine oxidase [flavin-containing] A [Heterocephalus glaber] >gi|617625010|ref|XP_007528286.1| PREDICTED: amine oxidase [flavin-containing] A [Erinaceus europaeus] >gi|586467491|ref|XP_006864355.1| PREDICTED: amine oxidase [flavin-containing] A [Chrysochloris asiatica] >gi|586526043|ref|XP_006917967.1| PREDICTED: amine oxidase [flavin-containing] A-like [Pteropus alecto] >gi|524961338|ref|XP_005080602.1| PREDICTED: amine oxidase [flavin-containing] A [Mesocricetus auratus] >gi|505838936|ref|XP_004612999.1| PREDICTED: amine oxidase [flavin-containing] A [Sorex araneus] >gi|554578713|ref|XP_005880942.1| PREDICTED: amine oxidase [flavin-containing] A [Myotis brandtii] >gi|504151382|ref|XP_004588039.1| PREDICTED: amine oxidase [flavin-containing] A [Ochotona princeps] >gi|560935202|ref|XP_006193430.1| PREDICTED: amine oxidase [flavin-containing] A [Camelus
Molecular Characterization of monoamine oxidase A
14 ferus] >gi|558133152|ref|XP_006090628.1| PREDICTED: LOW QUALITY PROTEIN: amine oxidase [flavin-containing] A [Myotis lucifugus] >gi|625270688|ref|XP_007626891.1| PREDICTED: amine oxidase [flavin-containing] A isoform X2, partial [Cricetulus griseus] >gi|634889379|ref|XP_007953802.1| PREDICTED: LOW QUALITY PROTEIN: amine oxidase [flavin-containing] A [Orycteropus afer afer] >gi|507691947|ref|XP_004713284.1| PREDICTED: amine oxidase [flavin-containing] A, partial [Echinops telfairi] >gi|620961138|ref|XP_007665426.1| PREDICTED: amine oxidase [flavin-containing] A isoform X1 [Ornithorhynchus anatinus] >gi|530624546|ref|XP_005301830.1| PREDICTED: amine oxidase [flavin-containing] A [Chrysemys picta bellii] >gi|470596203|ref|XP_004310916.1| PREDICTED: amine oxidase [flavin-containing] A [Tursiops truncatus] >gi|591379920|ref|XP_007064505.1| PREDICTED: amine oxidase [flavin-containing] A [Chelonia mydas] >gi|612016585|ref|XP_007493381.1| PREDICTED: amine oxidase [flavin-containing] A isoform X6 [Monodelphis domestica] >gi|564262979|ref|XP_006270360.1| PREDICTED: amine oxidase [flavin-containing] A [Alligator mississippiensis] >gi|558227956|ref|XP_006137957.1| PREDICTED: amine oxidase [flavin-containing] A isoform X1 [Pelodiscus sinensis] >gi|556995056|ref|XP_006001398.1| PREDICTED: amine oxidase [flavin-containing]-like [Latimeria chalumnae] >gi|612016583|ref|XP_007493380.1| PREDICTED: amine oxidase [flavin-containing] A isoform X5 [Monodelphis domestica] >gi|514460149|ref|XP_003469476.2| PREDICTED: amine oxidase [flavin-containing] A [Cavia porcellus] >gi|543366406|ref|XP_005526561.1| PREDICTED: amine oxidase [flavin-containing] B [Pseudopodoces humilis] >gi|426395653|ref|XP_004064080.1| PREDICTED: amine oxidase [flavin-containing] A isoform 2 [Gorilla gorilla gorilla] >gi|557260099|ref|XP_006015701.1| PREDICTED: amine oxidase [flavin-containing] A [Alligator sinensis] >gi|543721014|ref|XP_005501709.1| PREDICTED: amine oxidase [flavin-containing] B isoform X1 [Columba livia] >gi|543721016|ref|XP_005501710.1| PREDICTED: amine oxidase [flavin-containing] B isoform X2 [Columba livia] >gi|612016571|ref|XP_001377998.3| PREDICTED: amine oxidase [flavin-containing] B [Monodelphis domestica] >gi|530624548|ref|XP_005301831.1| PREDICTED: amine oxidase [flavin-containing] B [Chrysemys picta bellii] >gi|301606444|ref|XP_002932838.1| PREDICTED: amine oxidase [flavin-containing]-like [Xenopus (Silurana) tropicalis] >gi|327268401|ref|XP_003218986.1| PREDICTED: amine oxidase [flavin-containing] B-like [Anolis carolinensis] >gi|441673976|ref|XP_004092482.1| PREDICTED: amine oxidase [flavin-containing] A isoform 2
Molecular Characterization of monoamine oxidase A
15
[Nomascus leucogenys] >gi|617625023|ref|XP_007528290.1| PREDICTED: amine oxidase [flavin-containing] B [Erinaceus europaeus] >gi|589928227|ref|XP_006976936.1| PREDICTED: amine oxidase [flavin-containing] B [Peromyscus maniculatus bairdii] >gi|699629338|ref|XP_009902638.1| PREDICTED: amine oxidase [flavin-containing] B-like [Picoides pubescens] >gi|637283079|ref|XP_008105637.1| PREDICTED: amine oxidase [flavin-containing] A-like [Anolis carolinensis] >gi|701382733|ref|XP_009988386.1| PREDICTED: amine oxidase [flavin-containing] B-like [Tauraco erythrolophus] >gi|514715497|ref|XP_005012568.1| PREDICTED: amine oxidase [flavin-containing] B [Anas platyrhynchos] >gi|719756963|ref|XP_010215013.1| PREDICTED: amine oxidase [flavin-containing] B-like, partial [Tinamus guttatus] >gi|698464129|ref|XP_009704325.1| PREDICTED: amine oxidase [flavin-containing] B-like, partial [Cariama cristata] >gi|677598580|ref|XP_009081961.1| PREDICTED: amine oxidase [flavin-containing] B-like, partial [Acanthisitta chloris] >gi|686609523|ref|XP_009281385.1| PREDICTED: amine oxidase [flavin-containing] B-like [Aptenodytes forsteri] >gi|524978419|ref|XP_005037297.1| PREDICTED: amine oxidase [flavin-containing] B [Ficedula albicollis] >gi|586467415|ref|XP_006864317.1| PREDICTED: amine oxidase [flavin-containing] B [Chrysochloris asiatica] >gi|697496325|ref|XP_009677864.1| PREDICTED: amine oxidase [flavin-containing] B isoform X2 [Struthio camelus australis]
Molecular Characterization of monoamine oxidase A
16
Figure S3: Conserved sites in multiple sequence alignment using MEGA 6.0.
Molecular Characterization of monoamine oxidase A
17
Figure S4: Molecular phylogenetic analysis by Maximum Likelihood method for the MAO gene. A Maximum Likelihood tree was constructed (JTT model, Gamma distribution (5 categories, +G, parameter = 0.5703), Bootstrap (50)). [MAO-A= Monoamine oxidases A; MAO-B= Monoamine oxidases B; MAO-A I = isoform 1; MAO-A 2=isoform 2; MAO-A K=isoform K where K is a variant; unrooted tree] Phylogenetic analyses were performed in MEGA6.
Molecular Characterization of monoamine oxidase A
18
Figure S5: MAO-A gene expression in humans. [Source –TiGER]
Molecular Characterization of monoamine oxidase A
19 Table S1: Conserved sites in all 106 sequences. (Positions use the human MAO-A gene as the reference gene.)
Site in the Human MAO-A Amino Acid
174 A
177 F
179 N
183 T
185 E
189 V
190 S
192-197 LWFLWY
201-204 CGGT
206 R
212-219 NGGQERKF
221-222 GG
228 E
234 L
238 V
240 L
243-244 PV
249 Q
258 T
287-288 LP
294 L
321 C
326 I
338-339 DD
341-342 KP
351-353 GFI