SpermatogenesisOnline 1.0
 

Tag Content
SG ID
SG00002081 
UniProt Accession
Theoretical PI
5.78  
Molecular Weight
163785 Da  
Genbank Nucleotide ID
Genbank Protein ID
Gene Name
A2m 
Gene Synonyms/Alias
A2m1 
Protein Name
Alpha-2-macroglobulin 
Protein Synonyms/Alias
Alpha-2-MFlags: Precursor 
Organism
Rattus norvegicus (Rat) 
NCBI Taxonomy ID
10116 
Chromosome Location
chr:4;158103689-158153422;1
View in Ensembl genome browser  
Function in Stage
Function in Cell Type
Description
Temporarily unavailable 
The information of related literatures
1. L. J. Zhu, C. Y. Cheng, D. M. Phillips and C. W. Bardin (1994) The immunohistochemical localization of alpha 2-macroglobulin in rat testes is consistent with its role in germ cell movement and spermiation. J Androl 15(6): 575-82. 

Abstract
alpha 2-Macroglobulin (alpha 2-MG) is a nonspecific protease inhibitor and binding protein for peptide hormones that was recently isolated from Sertoli cell-enriched culture medium and shown to be the same protein as alpha 2-MG in serum. The present study was conducted to determine the localization of alpha 2-MG in the seminiferous epithelium in order to gain insight into its possible site(s) of action. Immunostainable alpha 2-MG was present in the lumen of the tubules consistent with its proposed role as a protease inhibitor needed to inactivate the protease released from defective spermatozoa in the male reproductive tract. Immunoreactive alpha 2-MG was also localized adjacent to the heads of elongated spermatids, the most mobile cells in the seminiferous epithelium; immunostainable alpha 2-MG was not observed adjacent to round spermatids and spermatocytes, which are relatively less mobile. The intensity of the staining around the elongated spermatids was dependent on the stage of the spermatogenic cycle. Stainable alpha 2-MG was present adjacent to the spermatids in stage XI soon after the elongation process began. Immunoreactive product was in stages XI-XIV but only faintly visible. The most intense staining reaction for alpha 2-MG was in stages I-VI; it was reduced in stage VII; and virtually no alpha 2-MG was detectable in stages VIII-X at and just after spermiation. The postnatal changes of alpha 2-MG in the testis was also examined. During the first 2 weeks after birth, alpha 2-MG was not detected in the seminiferous epithelium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID: [7536726] 

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Figures for illustrating the function of this protein/gene
Function
Is able to inhibit all four classes of proteinases by aunique 'trapping' mechanism. This protein has a peptide stretch,called the 'bait region' which contains specific cleavage sitesfor different proteinases. When a proteinase cleaves the baitregion, a conformational change is induced in the protein whichtraps the proteinase. The entrapped enzyme remains active againstlow molecular weight substrates (activity against high molecularweight substrates is greatly reduced). Following cleavage in thebait region a thioester bond is hydrolyzed and mediates thecovalent binding of the protein to the proteinase. 
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Subcellular Location
Secreted. 
Tissue Specificity
Highest constitutive expression in ovary. Lowlevel in testis, uterus and non-acute phase liver. Protein foundin plasma. 
Gene Ontology
GO IDGO termEvidence
GO:0005615 C:extracellular space IEA:InterPro.
GO:0004866 F:endopeptidase inhibitor activity NAS:UniProtKB.
GO:0004867 F:serine-type endopeptidase inhibitor activity IEA:UniProtKB-KW.
GO:0006953 P:acute-phase response IEP:RGD.
GO:0010037 P:response to carbon dioxide IEP:RGD.
GO:0051384 P:response to glucocorticoid stimulus IEP:RGD.
GO:0007584 P:response to nutrient IEP:RGD.
GO:0048863 P:stem cell differentiation IEA:Compara.
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Interpro
IPR009048;    A-macroglobulin_rcpt-bd.
IPR011626;    A2M_comp.
IPR002890;    A2M_N.
IPR011625;    A2M_N_2.
IPR001599;    Macroglobln_a2.
IPR019742;    MacrogloblnA2_CS.
IPR019565;    MacrogloblnA2_thiol-ester-bond.
IPR008930;    Terpenoid_cyclase/PrenylTrfase.
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Pfam
PF00207;    A2M;    1.
PF07678;    A2M_comp;    1.
PF01835;    A2M_N;    1.
PF07703;    A2M_N_2;    1.
PF07677;    A2M_recep;    1.
PF10569;    Thiol-ester_cl;    1.
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SMART
PROSITE
PS00477;    ALPHA_2_MACROGLOBULIN;    1.
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PRINTS
Created Date
18-Oct-2012 
Record Type
Experiment identified 
Protein sequence Annotation
SIGNAL        1     27
CHAIN        28   1472       Alpha-2-macroglobulin.
                             /FTId=PRO_0000000058.
REGION      620    750       Bait region.
CARBOHYD     59     59       N-linked (GlcNAc...) (Potential).
CARBOHYD     74     74       N-linked (GlcNAc...) (Potential).
CARBOHYD    250    250       N-linked (GlcNAc...) (Potential).
CARBOHYD    399    399       N-linked (GlcNAc...) (Potential).
CARBOHYD    651    651       N-linked (GlcNAc...) (Potential).
CARBOHYD    772    772       N-linked (GlcNAc...) (Potential).
CARBOHYD    867    867       N-linked (GlcNAc...) (Potential).
CARBOHYD    989    989       N-linked (GlcNAc...) (Potential).
CARBOHYD   1364   1364       N-linked (GlcNAc...) (Potential).
CARBOHYD   1422   1422       N-linked (GlcNAc...) (Potential).
CARBOHYD   1426   1426       N-linked (GlcNAc...) (Potential).
DISULFID     52     90       By similarity.
DISULFID    254    302       By similarity.
DISULFID    272    290       By similarity.
DISULFID    281    281       Interchain (with C-434) (By similarity).
DISULFID    434    434       Interchain (with C-281) (By similarity).
DISULFID    473    566       By similarity.
DISULFID    598    769       By similarity.
DISULFID    647    694       By similarity.
DISULFID    819    847       By similarity.
DISULFID    845    881       By similarity.
DISULFID    919   1319       By similarity.
DISULFID   1077   1125       By similarity.
DISULFID   1350   1465       By similarity.
CROSSLNK    970    973       Isoglutamyl cysteine thioester (Cys-Gln)
                             (By similarity).
CONFLICT     23     23       L -> V (in Ref. 3; CAA32164).
CONFLICT     72     72       R -> H (in Ref. 1; AAA40636 and 3;
                             CAA32164).
CONFLICT    103    103       V -> L (in Ref. 1; AAA40636 and 3;
                             CAA32164).
CONFLICT    120    120       R -> Q (in Ref. 1; AAA40636 and 3;
                             CAA32164).
CONFLICT    490    490       M -> L (in Ref. 4; AAA40638).
CONFLICT   1025   1025       T -> A (in Ref. 1; AAA40636).
CONFLICT   1192   1192       A -> G (in Ref. 1; AAA40636).
CONFLICT   1200   1200       P -> T (in Ref. 1; AAA40636).
CONFLICT   1279   1279       H -> R (in Ref. 1; AAA40636).
CONFLICT   1340   1340       T -> A (in Ref. 1; AAA40636).
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Nucleotide Sequence
Length: 4595 bp   Go to nucleotide: FASTA
Protein Sequence
Length: 1472 bp   Go to amino acid: FASTA
The verified Protein-Protein interaction information
UniProt
 Gene Symbol Ref Databases
Other Protein-Protein interaction resources
String database  
View Microarray data
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