Androgen-binding protein, Sex hormone-binding globulin
Identifiers
Symbol	SHBG
Alt. symbols	ABP
Entrez	6462
HUGO	10839
OMIM	182205
RefSeq	NM_001040
UniProt	P04278
Other data
Locus	Chr. 17 p13-p12

Androgen-binding protein (ABP) is a glycoprotein (beta-globulin) produced by the Sertoli cells in the seminiferous tubules of the testis that binds specifically to testosterone (T), dihydrotestosterone (DHT), and 17-beta-estradiol.

By binding to T and DHT these hormones are made less lipophilic and become concentrated within the luminal fluid of the seminiferous tubules. The higher levels of these hormones enable spermatogenesis in the seminiferous tubules and sperm maturation in the epididymis.

ABP has the same amino acid sequence as sex hormone-binding globulin (SHBG); the difference is the site of production and the addition of different sugar moieties. ABP contains 403 amino acids resulting in a molecular weight of 44,533. Its gene is located on chromosome 17.

ABP’s production is regulated under influence of FSH on Sertoli cell, enhanced by insulin, retinol, and testosterone.

ABP may also be secreted in other organs, for instance mice produce a salivary ABP.

[edit] See also

• SHBG

[edit] References

• Ensembl Gene ref Protein ref

[edit] External links

• MeSH Androgen-Binding+Protein

v • d • e Proteins: carrier proteins Fatty acid FABP1 · FABP2 · FABP3 · FABP4 · FABP5 · FABP6 · FABP7 Hormone Follistatin · Growth hormone binding protein · Insulin-like growth factor binding protein (IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, IGFBP6, IGFBP7) · Neurophysins (Neurophysin I, II) Sex hormone binding globulin/Androgen binding protein · Transcortin · Thyroxine-binding globulin · Transthyretin Metal/element calcium (Calcium-binding protein, Calmodulin-binding proteins) · copper (Ceruloplasmin) · iron (Iron-binding proteins, Transferrin receptor) Vitamin Retinol binding protein (4) · Transcobalamin Other Acyl carrier protein · Adaptor protein · Cholesterylester transfer protein · F-box protein · GTP-binding protein · Latent TGF-beta binding protein · Light-harvesting complex · Membrane transport protein