A steroid/thyroid hormone receptor superfamily in Drosophila melanogaster that shares extensive sequence similarity with a mammalian counterpart

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Vincent C. Henrich, Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: A gene in Drosophila melanogaster that maps cytologlcally to 2C1 — 3 on the distal portion of the X-chromosome encodes a member of the steroid/thyrold hormone receptor superfamily. The gene was isolated from an embryonic cDNA library using an oligonucleotide probe that specifies the consensus amino acid sequence in the DNA-binding domain of several human receptors. The conceptual amino acld sequence of 2C reveals at least four regions of homology that are shared with all identified vertebrate receptors. Reglon I includes the two cysteine-cysteine zinc fingers that comprlse a DNA-bindlng domaln which typifies all members of the superfamily. ln addition, three regions (Regions lI-IV) in the carboxy-termlnal portion of the protein that encode the putative hormone-binding domain of the 2C gene product resemble similar sequences ln vertebrate steroid/thyroid hormone receptors. The similarity suggests that this Drosophila receptor possesses many of the regulatory functions attributed to these regions in vertebrate counterparts. A portion of Region II also resembles part of the human c-jun oncoprotein's leucine zipper, which in turn, has been demonstrated to be the heterodimerlzation site between the jun and fos oncoproteins. The 2C receptor-llke protein most resembles the mouse H2RII binding protein, a member of the superfamily which has been implicated in the regulatlon of major histocompatibility complex (MHC) class I gene expression. These two gene products are 83% ldentical in the DNA-binding domain and 50% identical in the putative hormone-binding domain, although no ligand has been identified for either protein. The high degree of simllarity in the hormone-blnding domaln between the 2C protein and the H2RII binding protein outside regions II-IV suggests specific functional roles which are not shared by other members of the superfamily.

Additional Information

Nucleic Acids Research
Language: English
Date: 1990
Drosophila melanogaster, genetics, biology

Email this document to