home *** CD-ROM | disk | FTP | other *** search
- *****************************************
- * Thyroglobulin type-1 repeat signature *
- *****************************************
-
- 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 10 repeats of
- a domain of about 65 amino acids which is known as the Tg type-1 repeat [1].
- Such a domain has also been found (as a single copy) in the proteins listed
- below:
-
- - In the HLA class II associated invariant chain [2]. 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 [3].
- - 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) [4].
-
- The central part of the domain is well conserved and contains four cysteines.
- We have used this region as a signature pattern.
-
- -Consensus pattern: [FYWHP]-x-P-x-C-x(3,4)-G-x-[FYW]-x(3)-Q-C-x(4,10)-C-[FYW]-
- C-V-x(3,4)-[SG]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: December 1992 / Text revised.
-
- [ 1] Malthiery Y., Lissitzky S.
- Eur. J. Biochem. 165:491-498(1987).
- [ 2] Koch N., Lauer W., Habicht J., Dobberstein B.
- EMBO J. 6:1677-1683(1987).
- [ 3] Szala S., Froehlich M., Scollon M., Kasai Y., Steplewski Z.,
- Koprowski H., Linnenbach A.J.
- Proc. Natl. Acad. Sci. U.S.A. 87:3542-3546(1990).
- [ 4] Kiefer M.C., Masiarz F.R., Bauer D.M., Zapf J.
- J. Biol. Chem. 266:9043-9049(1991).
-