Details for: AMY2B

Gene ID: 280

Gene Type:  Protein-coding  - A gene that serves as a template for producing a messenger RNA (mRNA) molecule, which is then translated into a functional protein.

Symbol: AMY2B

Ensembl ID: ENSG00000240038

Description: amylase alpha 2B

Selected Context(s):  Overall

Cell Significance Landscape

Contexts:

Associated with

Significant Cells

Cell Significance Index (CSI) scores for the chosen context(s)

  • pancreatic acinar cell CL0002064
    CSI 7.14
    rCSI 9.49%
    PRS 97.13
  • L5 extratelencephalic projecting glutamatergic cortical neuron CL4023041
    CSI 6.09
    rCSI 21.93%
    PRS 88.01
  • melanocyte CL0000148
    CSI 3.8
    rCSI 2.82%
    PRS 94.38
  • pvalb GABAergic cortical interneuron CL4023018
    CSI 3.48
    rCSI 4.32%
    PRS 87.79
  • retinal bipolar neuron CL0000748
    CSI 3.25
    rCSI 6.09%
    PRS 91.54
  • cardiac muscle cell CL0000746
    CSI 3.22
    rCSI 4.62%
    PRS 91.33
  • near-projecting glutamatergic cortical neuron CL4023012
    CSI 3.14
    rCSI 11.85%
    PRS 89.42
  • adipocyte CL0000136
    CSI 3.06
    rCSI 3.93%
    PRS 91.52
  • cerebral cortex endothelial cell CL1001602
    CSI 2.96
    rCSI 5.11%
    PRS 93.65
  • inhibitory interneuron CL0000498
    CSI 2.92
    rCSI 6.75%
    PRS 91
  • vascular leptomeningeal cell CL4023051
    CSI 2.9
    rCSI 5.08%
    PRS 94.53
  • astrocyte of the cerebral cortex CL0002605
    CSI 2.67
    rCSI 5.99%
    PRS 89.71
  • ciliated columnar cell of tracheobronchial tree CL0002145
    CSI 2.57
    rCSI 5.87%
    PRS 91.08
  • L6b glutamatergic cortical neuron CL4023038
    CSI 2.49
    rCSI 7.78%
    PRS 90.2
  • kidney loop of Henle thin descending limb epithelial cell CL1001111
    CSI 2.46
    rCSI 3.48%
    PRS 95.17
  • corticothalamic-projecting glutamatergic cortical neuron CL4023013
    CSI 2.45
    rCSI 14.42%
    PRS 89.71
  • sst GABAergic cortical interneuron CL4023017
    CSI 2.43
    rCSI 3.13%
    PRS 90.25
  • caudal ganglionic eminence derived cortical interneuron CL4023064
    CSI 2.33
    rCSI 4.11%
    PRS 89.09
  • GABAergic neuron CL0000617
    CSI 2.29
    rCSI 7.66%
    PRS 87.52
  • VIP GABAergic cortical interneuron CL4023016
    CSI 2.28
    rCSI 2.73%
    PRS 89.53
  • amacrine cell CL0000561
    CSI 2.22
    rCSI 6.42%
    PRS 91.14
  • L4 intratelencephalic projecting glutamatergic neuron CL4030063
    CSI 2.09
    rCSI 5%
    PRS 89.62
  • sncg GABAergic cortical interneuron CL4023015
    CSI 2.05
    rCSI 3.3%
    PRS 90.06
  • L2/3-6 intratelencephalic projecting glutamatergic neuron CL4023040
    CSI 2.05
    rCSI 4.97%
    PRS 87.81
  • cardiac neuron CL0010022
    CSI 1.79
    rCSI 5.72%
    PRS 95.64
  • retinal ganglion cell CL0000740
    CSI 1.65
    rCSI 3.64%
    PRS 90.15
  • retinal cone cell CL0000573
    CSI 1.61
    rCSI 2.6%
    PRS 91.11
  • regular atrial cardiac myocyte CL0002129
    CSI 1.44
    rCSI 4.63%
    PRS 93.59
  • chandelier pvalb GABAergic cortical interneuron CL4023036
    CSI 1.43
    rCSI 4.47%
    PRS 91.36
  • direct pathway medium spiny neuron CL4023026
    CSI 1.43
    rCSI 34.19%
    PRS 87.27
  • kidney connecting tubule epithelial cell CL1000768
    CSI 1.41
    rCSI 3.57%
    PRS 93.21
  • indirect pathway medium spiny neuron CL4023029
    CSI 1.4
    rCSI 33.85%
    PRS 86.99
  • lamp5 GABAergic cortical interneuron CL4023011
    CSI 1.34
    rCSI 2.24%
    PRS 89.48
  • regular ventricular cardiac myocyte CL0002131
    CSI 1.29
    rCSI 8.06%
    PRS 92.08
  • parietal epithelial cell CL1000452
    CSI 1.26
    rCSI 3.37%
    PRS 93.59
  • L5/6 near-projecting glutamatergic neuron CL4030067
    CSI 1.16
    rCSI 3.83%
    PRS 88.53
  • central nervous system neuron CL2000029
    CSI 0.65
    rCSI 4.77%
    PRS 91.71
  • kidney distal convoluted tubule epithelial cell CL1000849
    CSI 0.6
    rCSI 6.37%
    PRS 93.5
  • ON parasol ganglion cell CL4033052
    CSI 0.49
    rCSI 6.99%
    PRS 90.84

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this specific cell.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.
Network Configuration

Explore relationships of the current gene. Select an Interaction Source: 'ONTOLOGY' for shared pathways (GO/Reactome) or 'STRING' for protein-protein interactions. Further refine by selecting context genes and comparing Cell Significance Index (CSI) scores between baseline and target cell types and their specific contexts.

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  • Node Color (Target Cell CSI, relative to current network):
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    • High
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    • Very Low
    • CSI N/A
  • Node Size: Proportional to Target Cell CSI magnitude
  • STRING PPI Edge
  • Shared Pathway Edge (ONTOLOGY)

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Other Information

This section provides additional information about the gene, including a description generated by an AI language model and details about associated proteins.

## Summary [AMY2B](/details-gene/280), or Amylase Alpha 2B, is a protein-coding gene located on chromosome 1p21.1 that encodes a key enzyme in carbohydrate metabolism. As a member of the alpha-amylase family, its canonical function is the hydrolysis of starch and glycogen, a critical step in the digestion of dietary carbohydrates. This is strongly supported by its exceptionally high expression in [pancreatic acinar cells](/details-cell/CL0002064), the primary source of digestive enzymes. However, expression data also reveals a surprisingly significant presence in various neuronal subtypes, including [L5 extratelencephalic projecting glutamatergic cortical neurons](/details-cell/CL4023041), suggesting potential non-canonical roles for [AMY2B](/details-gene/280) within the central nervous system and other tissues. Early research identified this specific amylase gene and characterized its distinct amino-acid sequence ([Link](https://pubmed.ncbi.nlm.nih.gov/8268204/), [Link](https://pubmed.ncbi.nlm.nih.gov/2401405/)). Clinically, variations in amylase genes are cataloged under OMIM entry [104660](https://omim.org/entry/104660). ## Cellular Roles and Expression Landscape The expression profile of [AMY2B](/details-gene/280) highlights a dual identity: a dominant, well-established role in digestion and a secondary, more enigmatic presence in the nervous system and other tissues. **Overall**, the gene's significance is overwhelmingly highest in the [pancreatic acinar cell](/details-cell/CL0002064) (CSI: 7.14), consistent with its function as a secreted digestive enzyme. This cell type is specialized for producing and releasing large quantities of enzymes into the digestive tract. Beyond the pancreas, [AMY2B](/details-gene/280) shows a remarkably high significance score in several distinct neuronal populations. It is the second most significant marker in [L5 extratelencephalic projecting glutamatergic cortical neurons](/details-cell/CL4023041) (CSI: 6.09) and also ranks highly in [pvalb GABAergic cortical interneurons](/details-cell/CL4023018) (CSI: 3.48) and [retinal bipolar neurons](/details-cell/CL0000748) (CSI: 3.25). This pattern suggests that [AMY2B](/details-gene/280) may be involved in local carbohydrate metabolism within these specific neurons, potentially providing a rapid energy source for high-demand processes like synaptic transmission. Furthermore, the data indicates notable expression in a diverse array of other cell types, including [melanocytes](/details-cell/CL0000148) (CSI: 3.80), [cardiac muscle cells](/details-cell/CL0000746) (CSI: 3.22), and [adipocytes](/details-cell/CL0000136) (CSI: 3.06). This widespread, yet cell-type-specific, expression pattern suggests that the role of [AMY2B](/details-gene/280) may be more pleiotropic than previously understood, extending beyond its classical digestive function. ## Pathways and Molecular Function The annotated functions of [AMY2B](/details-gene/280) align perfectly with its primary role in digestion. Its molecular function is defined as [alpha-amylase activity](/details-go/GO:0004556), contributing to the broader biological process of [carbohydrate metabolic process](/details-go/GO:0005975). As a secreted protein, it is primarily found in the [extracellular space](/details-go/GO:0005615) and has been identified within [extracellular exosomes](/details-go/GO:0070062), which may represent a mechanism for its transport. These functions are integral to the Reactome pathways for [Digestion](/details-reactome/R-HSA-8935690), [Digestion and absorption](/details-reactome/R-HSA-8963743), and specifically the [Digestion of dietary carbohydrate](/details-reactome/R-HSA-189085). This molecular machinery is most relevant in the context of its high expression in [pancreatic acinar cells](/details-cell/CL0002064), which synthesize and secrete this enzyme into the small intestine. However, these annotations do not fully explain its high significance in neuronal or muscle cells, pointing towards undiscovered local functions in these microenvironments. ## Research Directions The unexpected expression of [AMY2B](/details-gene/280) in the central nervous system presents a compelling area for future investigation. While its digestive function is well-characterized, its role in neurons remains largely unexplored. The observation of its production in a lung carcinoid tumor also opens avenues related to cancer metabolism ([Link](https://pubmed.ncbi.nlm.nih.gov/2701942/)). ### Proposed Hypotheses 1. **[AMY2B](/details-gene/280) supports high-energy synaptic activity through local glycogenolysis in cortical neurons.** The high expression in specific neuronal subtypes, such as [L5 extratelencephalic projecting glutamatergic cortical neurons](/details-cell/CL4023041), suggests it may function intracellularly or in the immediate synaptic cleft to break down local glycogen stores, providing a rapid source of glucose to fuel energetically demanding processes like neurotransmission and synaptic plasticity. 2. **Ectopic expression of [AMY2B](/details-gene/280) confers a metabolic advantage to certain cancer cells.** Building on reports of its expression in lung carcinoid tumors, it is plausible that some cancer cells reactivate [AMY2B](/details-gene/280) expression to scavenge complex carbohydrates from the tumor microenvironment, providing an alternative fuel source to support rapid proliferation, particularly under hypoxic or nutrient-poor conditions. ### Experimental Approach To test the hypothesis regarding the neuronal function of [AMY2B](/details-gene/280) (Hypothesis 1), a multi-faceted approach could be employed. A conditional knockout mouse model could be generated to specifically delete *Amy2b* in glutamatergic neurons (e.g., using a vGlut-Cre driver line). Brain slices from these knockout animals and wild-type littermates could then be analyzed using electrophysiology to measure synaptic transmission and long-term potentiation (LTP). Concurrently, advanced imaging techniques, such as two-photon microscopy with fluorescent glucose sensors, could be used *in vivo* to determine if *Amy2b*-deficient neurons exhibit impaired glucose utilization or altered metabolic responses to stimuli. ### Therapeutic Potential Given its role as a secreted enzyme, [AMY2B](/details-gene/280) is a potentially druggable target. While modulating its function in the pancreas for digestive disorders is a possibility, its ectopic expression in cancer presents a more immediate therapeutic opportunity. If certain tumors are dependent on its alpha-amylase activity for survival, a strategy of **inhibition** could be pursued. A highly specific small molecule inhibitor designed to block the active site of [AMY2B](/details-gene/280) could serve as a targeted therapy to selectively starve cancer cells that have co-opted this metabolic pathway, potentially with minimal side effects on its canonical digestive function.

Genular Protein ID: 2854292858

Symbol: AMY2B_HUMAN

Name: Alpha-amylase 2B

UniProtKB Accession Codes:

P19961 B3KTI1 B3KXB7 D3DT76 Q9UBH3

Database IDs:

AGR 1 AlphaFoldDB 1 Antibodypedia 1 Bgee 1 BioGRID 1 BioGRID-ORCS 1 BioMuta 1 CAZy 1 CCDS 1 CDD 1 CTD 1 ChEBI 9 ChiTaRS 1 DMDM 1 DNASU 1 DisGeNET 1 DrugBank 9 EC 1 EMBL 12 Ensembl 3 ExpressionAtlas 1 GO 5 Gene3D 2 GeneCards 1 GeneTree 1 GeneWiki 1 GenomeRNAi 1 HGNC 1 HOGENOM 1 HPA 1 InParanoid 1 IntAct 1 InterPro 6 KEGG 1 MANE-Select 1 MIM 1 MassIVE 1 NCBI Taxonomy 1 OMA 1 OpenTargets 1 OrthoDB 1 PANTHER 2 PIR 1 PRIDE 1 PRINTS 1 PRO 1 PathwayCommons 1 PaxDb 1 PeptideAtlas 1 Pfam 2 PharmGKB 1 Pharos 1 PhosphoSitePlus 1 PhylomeDB 1 Proteomes 1 ProteomicsDB 2 Pumba 1 RNAct 1 Reactome 1 RefSeq 1 SMART 2 SMR 1 STRING 1 SUPFAM 2 SignaLink 1 TopDownProteomics 1 TreeFam 1 UCSC 1 VEuPathDB 1 eggNOG 1 iPTMnet 1 jPOST 1 neXtProt 1

Citations:

PubMed ID: 2701942

Title: A novel type of human alpha-amylase produced in lung carcinoid tumor.

PubMed ID: 2701942

DOI: 10.1016/0378-1119(89)90003-6

PubMed ID: 2401405

Title: Cloning and characterization of a third type of human alpha-amylase gene, AMY2B.

PubMed ID: 2401405

DOI: 10.1016/0378-1119(90)90191-s

PubMed ID: 14702039

Title: Complete sequencing and characterization of 21,243 full-length human cDNAs.

PubMed ID: 14702039

DOI: 10.1038/ng1285

PubMed ID: 16710414

Title: The DNA sequence and biological annotation of human chromosome 1.

PubMed ID: 16710414

DOI: 10.1038/nature04727

PubMed ID: 15489334

Title: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

PubMed ID: 15489334

DOI: 10.1101/gr.2596504

PubMed ID: 2452973

Title: Concerted evolution of human amylase genes.

PubMed ID: 2452973

DOI: 10.1128/mcb.8.3.1197-1205.1988

PubMed ID: 3260028

Title: Human pancreatic amylase is encoded by two different genes.

PubMed ID: 3260028

DOI: 10.1093/nar/16.10.4724

PubMed ID: 8268204

Title: Identification of the characteristic amino-acid sequence for human alpha-amylase encoded by the AMY2B gene.

PubMed ID: 8268204

DOI: 10.1016/0167-4838(93)90087-8

Sequence Information:

  • Length: 511
  • Mass: 57710
  • Checksum: 05FC3B1EC1143857
  • Sequence:
    • MKFFLLLFTI GFCWAQYSPN TQQGRTSIVH LFEWRWVDIA LECERYLAPK GFGGVQVSPP 
NENVAIHNPF RPWWERYQPV SYKLCTRSGN EDEFRNMVTR CNNVGVRIYV DAVINHMSGN 
AVSAGTSSTC GSYFNPGSRD FPAVPYSGWD FNDGKCKTGS GDIENYNDAT QVRDCRLVGL 
LDLALEKDYV RSKIAEYMNH LIDIGVAGFR LDASKHMWPG DIKAILDKLH NLNSNWFPAG 
SKPFIYQEVI DLGGEPIKSS DYFGNGRVTE FKYGAKLGTV IRKWNGEKMS YLKNWGEGWG 
FMPSDRALVF VDNHDNQRGH GAGGASILTF WDARLYKMAV GFMLAHPYGF TRVMSSYRWP 
RQFQNGNDVN DWVGPPNNNG VIKEVTINPD TTCGNDWVCE HRWRQIRNMV NFRNVVDGQP 
FTNWYDNGSN QVAFGRGNRG FIVFNNDDWT FSLTLQTGLP AGTYCDVISG DKINGNCTGI 
KIYVSDDGKA HFSISNSAED PFIAIHAESK L