Design of DNA-binding peptides based on the leucine zipper motif

Science ◽  
1990 ◽  
Vol 249 (4970) ◽  
pp. 774-778 ◽  
Author(s):  
K. O'Neil ◽  
R. Hoess ◽  
W. DeGrado
2020 ◽  
Author(s):  
Monare Thulo ◽  
Megan A Rabie ◽  
Naadira Pahad ◽  
Heather L Donald ◽  
Ashleigh A Blane ◽  
...  

FOX proteins are a superfamily of transcription factors which share a DNA binding domain referred to as the forkhead domain. Our focus is on the FOXP subfamily members, which are involved in language and cognition amongst other things. The FOXP proteins contain a conserved zinc finger and a leucine zipper motif in addition to the forkhead domain. The remainder of the sequence is predicted to be unstructured and includes an acidic C-terminal tail. In this study we aim to investigate how both the structured and unstructured regions of the sequence cooperate so as to enable FOXP proteins to perform their function. We do this by studying the effect of these regions on both oligomerisation and DNA binding. Structurally, the FOXP proteins appear to be comparatively globular with a high proportion of helical structure. The proteins multimerise via the leucine zipper and the stability of the multimers is controlled by the unstructured interlinking sequence including the acid rich tail. FOXP2 is more compact than FOXP1, has a greater propensity to form higher order oligomers, and binds DNA with stronger affinity. We conclude that while the forkhead domain is necessary for DNA binding, the affinity of the binding event is attributable to the leucine zipper, and the unstructured regions play a significant role in the specificity of binding. The acid rich tail forms specific contacts with the forkhead domain which may influence oligomerisation and DNA binding and therefore the acid rich tail may play an important regulatory role in FOXP transcription. 


Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 859-869 ◽  
Author(s):  
Patrick J Ferris ◽  
Ursula W Goodenough

Diploid cells of Chlamydomonas reinhardtii that are heterozygous at the mating-type locus (mt  +/mt  –) differentiate as minus gametes, a phenomenon known as minus dominance. We report the cloning and characterization of a gene that is necessary and sufficient to exert this minus dominance over the plus differentiation program. The gene, called mid, is located in the rearranged (R) domain of the mt  – locus, and has duplicated and transposed to an autosome in a laboratory strain. The imp11 mt  – mutant, which differentiates as a fusion-incompetent plus gamete, carries a point mutation in mid. Like the fus1 gene in the mt  + locus, mid displays low codon bias compared with other nuclear genes. The mid sequence carries a putative leucine zipper motif, suggesting that it functions as a transcription factor to switch on the minus program and switch off the plus program of gametic differentiation. This is the first sex-determination gene to be characterized in a green organism.


1990 ◽  
Vol 10 (4) ◽  
pp. 1347-1357
Author(s):  
C J Kara ◽  
H C Liou ◽  
L B Ivashkiv ◽  
L H Glimcher

The cyclic AMP response element (CRE) is found in many cellular genes regulated by cyclic AMP, and similar elements are present in the early genes of adenovirus that are activated by E1A. The transcription factor CREB has previously been shown to bind this site, and cDNAs for CREB have recently been characterized. We report here the isolation of a cDNA encoding a human DNA-binding protein that also recognizes this motif in cellular and viral promoters. This protein, HB16, displays structural similarity to CREB and to c-Jun and c-Fos, which bind the related 12-O-tetradecanoylphorbol-13-acetate response element (TRE). HB16 contains a highly basic, putative DNA-binding domain and a leucine zipper structure thought to be involved in dimerization. Deletional analysis of HB16 demonstrated that the leucine zipper is required for its interaction with DNA. In addition, HB16 could form a complex with c-Jun but not with c-Fos. Despite its structural similarity to c-Jun and c-Fos and its interaction with c-Jun, HB16 had approximately a 10-fold-lower affinity for the TRE sequence than for the CRE sequence. Although HB16 and CREB both recognized the CRE motif, an extensive binding analysis of HB16 revealed differences in the fine specificity of binding of the two proteins. HB16 mRNA was found at various levels in many human tissues but was most abundant in brain, where its expression was widespread. The existence of more than one CRE-binding protein suggests that the CRE motif could serve multiple regulatory functions.


1990 ◽  
Vol 10 (4) ◽  
pp. 1347-1357 ◽  
Author(s):  
C J Kara ◽  
H C Liou ◽  
L B Ivashkiv ◽  
L H Glimcher

The cyclic AMP response element (CRE) is found in many cellular genes regulated by cyclic AMP, and similar elements are present in the early genes of adenovirus that are activated by E1A. The transcription factor CREB has previously been shown to bind this site, and cDNAs for CREB have recently been characterized. We report here the isolation of a cDNA encoding a human DNA-binding protein that also recognizes this motif in cellular and viral promoters. This protein, HB16, displays structural similarity to CREB and to c-Jun and c-Fos, which bind the related 12-O-tetradecanoylphorbol-13-acetate response element (TRE). HB16 contains a highly basic, putative DNA-binding domain and a leucine zipper structure thought to be involved in dimerization. Deletional analysis of HB16 demonstrated that the leucine zipper is required for its interaction with DNA. In addition, HB16 could form a complex with c-Jun but not with c-Fos. Despite its structural similarity to c-Jun and c-Fos and its interaction with c-Jun, HB16 had approximately a 10-fold-lower affinity for the TRE sequence than for the CRE sequence. Although HB16 and CREB both recognized the CRE motif, an extensive binding analysis of HB16 revealed differences in the fine specificity of binding of the two proteins. HB16 mRNA was found at various levels in many human tissues but was most abundant in brain, where its expression was widespread. The existence of more than one CRE-binding protein suggests that the CRE motif could serve multiple regulatory functions.


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