PROSITE documentation PDOC00377Thyroglobulin type-1 domain signature and profile
Thyroglobulin (Tg) is a large glycoprotein specific to the thyroid gland and it is the precursor of the iodinated thyroid hormones thyroxine (T4) and triiodothyronine (T3). The N-terminal section of Tg contains 11 repeats of a domain of about 70 amino acids which is known as the Tg type-1 repeat [1,2,3]. Such a domain has also been found (as a single or repeated sequence) in the proteins listed below:
- In the HLA class II associated invariant chain [3]. In that protein the type-1 repeat is encoded by an exon which is alternatively spliced and is only present in a longer form of the protein.
- In human pancreatic carcinoma marker proteins GA733-1 and GA733-2 (which is also known as epithelial cell surface antigen (EPG) or adenocarcinoma- associated antigen (KSA) or antigen KS 1/4). These proteins may function as growth factor receptors [4].
- In nidogen (entactin), a sulfated glycoprotein which is widely distributed in basement membranes and that is tightly associated with laminin. Nidogen probably has a role in cell-extracellular matrix interactions.
- In the insulin-like growth factor binding proteins (IGFBP) [5] (see <PDOC00194>).
- In saxiphilin, a transferrin-like protein from frog that binds specifically to the neurotoxin saxitoxin [6].
- In equistatin, a thiol-protease inhibitor from sea anemone [7].
The domain contains six cysteines (Tg type-1a) involved in 3 disulfide bonds (see <PDB:1ZT3>) [5], but also exists in a variant that lacks the third and fourth cysteines (Tg type-1b). One Gln residue is strongly conserved. Schematic representations of the two Tg type-1 domains are shown below:
Tg type-1a: +-------------------+ +------+ +--------------------+ | | | | | | xxxCxxxxxxxxxxxxxxxxxxxCxxxxxxxxxQCxxxxxxCxCxxxxxxxxxxxxxxxxxxxxC ******************************* Tg type-1b: +-------------------+ +--------------------+ | | | | xxxCxxxxxxxxxxxxxxxxxxxCxxxxxxxxxQxxxxxxxxxCxxxxxxxxxxxxxxxxxxxxC *******************************
'C': Conserved cysteine involved in a disulfide bond. '*': Position of the consensus pattern in the domain.
The central part of the domain is well conserved, we have used this region as a signature pattern for Tg type-1 domains. We also developed a profile which covers the entire Tg type-1 domain.
Expert(s) to contact by email: Last update:November 2005 / Text revised; profile added.
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PROSITE methods (with tools and information) covered by this documentation:
1 | Authors | Malthiery Y. Lissitzky S. |
Title | Primary structure of human thyroglobulin deduced from the sequence of its 8448-base complementary DNA. | |
Source | Eur. J. Biochem. 165:491-498(1987). | |
PubMed ID | 3595599 |
2 | Authors | Molina F. Bouanani M. Pau B. Granier C. |
Title | Characterization of the type-1 repeat from thyroglobulin, a cysteine-rich module found in proteins from different families. | |
Source | Eur. J. Biochem. 240:125-133(1996). | |
PubMed ID | 8797845 |
3 | Authors | Guncar G. Pungercic G. Klemencic I. Turk V. Turk D. |
Title | Crystal structure of MHC class II-associated p41 Ii fragment bound to cathepsin L reveals the structural basis for differentiation between cathepsins L and S. | |
Source | EMBO J. 18:793-803(1999). | |
PubMed ID | 10022822 | |
DOI | 10.1093/emboj/18.4.793 |
4 | Authors | Szala S. Froehlich M. Scollon M. Kasai Y. Steplewski Z. Koprowski H. Linnenbach A.J. |
Title | Molecular cloning of cDNA for the carcinoma-associated antigen GA733-2. | |
Source | Proc. Natl. Acad. Sci. U.S.A. 87:3542-3546(1990). | |
PubMed ID | 2333300 |
5 | Authors | Sala A. Capaldi S. Campagnoli M. Faggion B. Labo S. Perduca M. Romano A. Carrizo M.E. Valli M. Visai L. Minchiotti L. Galliano M. Monaco H.L. |
Title | Structure and properties of the C-terminal domain of insulin-like growth factor-binding protein-1 isolated from human amniotic fluid. | |
Source | J. Biol. Chem. 280:29812-29819(2005). | |
PubMed ID | 15972819 | |
DOI | 10.1074/jbc.M504304200 |
6 | Authors | Morabito M.A. Moczydlowski E. |
Title | Molecular cloning of bullfrog saxiphilin: a unique relative of the transferrin family that binds saxitoxin. | |
Source | Proc. Natl. Acad. Sci. U.S.A. 91:2478-2482(1994). | |
PubMed ID | 8146142 |
7 | Authors | Lenarcic B. Ritonja A. Strukelj B. Turk B. Turk V. |
Title | Equistatin, a new inhibitor of cysteine proteinases from Actinia equina, is structurally related to thyroglobulin type-1 domain. | |
Source | J. Biol. Chem. 272:13899-13903(1997). | |
PubMed ID | 9153250 |
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