HMG box gene transcriptions
{{free media}}"Upstream Binding Factor (UBF) is important for activation of ribosomal RNA transcription and belongs to a family of proteins containing nucleic acid binding domains, termed HMG-boxes, with similarity to High Mobility Group (HMG) chromosomal proteins."[1]
Chromosomal proteins
"Most HMG box proteins contain two or more HMG boxes and appear to bind DNA in a relatively sequence-aspecific manner (5, 13, 15, 16 and references therein). [...] they all appear to bind to the minor groove of the A/T A/T C A A A G-motif (10, 14, 18-20)."[2]
"Previous studies in lymphocytes have described two DNA-binding HMG box proteins, TCF-1 and LEF-1, with affinity for the A/TA/TCAAAG motif found in several T cell-specific enhancers."[3]
"The high mobility group-1 (HMG) box was originaly identified by Tjian and co-workers in the transcription factor UBF as a region of homology to HMG-1 proteins (Jantzen et al., 1990). UBF reportedly contained four such regions of -80 amino acids; one of these boxes was shown to mediate DNA binding."[3]
"Interestingly, the sequence-specific HMG boxes characterized to date display high afinity to the A/TA/TCAAAG motif despite a low level of amino acid homology (typically <25% identity)."[3]
"Human LEF-1 was originally identified as a T cell-specific protein binding to the TTCAAAG motif in the TCR-α enhancer (Waterman et al., 1991)."[3]
"As analysed by gel retardation, the Sox-4 HMG box indeed bound to the AACAAAG motif (probe MWε-1; Figure 2B, lane 1). As described for other HMG boxes, Sox-4 interacted with DNA bases within the minor groove: substitution of A/T pairs for I/C pairs, which leaves the surface of the minor groove intact (Star and Hawley, 1991), had no apparent effect on binding affinity (lanes 2 and 4)."[3]
Consensus sequences
"In mammals, the Tcf/Lef family consists of four genes: Tcf‐1, Lef‐1, Tcf‐3 and Tcf‐4. All TCF/LEF proteins display several common structural features (48,49). They contain a nearly identical DNA‐binding domain, the HMG box, recognizing the consensus sequence A/T A/T CAAA."[4]
High mobility group proteins
Gene ID: 51176 is LEF1 lymphoid enhancer binding factor 1: "This gene encodes a transcription factor belonging to a family of proteins that share homology with the high mobility group protein-1. The protein encoded by this gene can bind to a functionally important site in the T-cell receptor-alpha enhancer, thereby conferring maximal enhancer activity. This transcription factor is involved in the Wnt signaling pathway, and it may function in hair cell differentiation and follicle morphogenesis. Mutations in this gene have been found in somatic sebaceous tumors. This gene has also been linked to other cancers, including androgen-independent prostate cancer. Alternative splicing results in multiple transcript variants."[5]
- NP_001124185.1 lymphoid enhancer-binding factor 1 isoform 2: "Transcript Variant: This variant (2) lacks an alternate in-frame exon in the central coding region, compared to variant 1, resulting in an isoform (2) that is shorter than isoform 1. [...] SOX-TCF_HMG-box, class I member of the HMG-box superfamily of DNA-binding proteins. These proteins contain a single HMG box, and bind the minor groove of DNA in a highly sequence-specific manner. Members include SRY and its homologs in insects and vertebrates, and transcription factor-like proteins, TCF-1, -3, -4, and LEF-1. They appear to bind the minor groove of the A/T C A A A G/C-motif."[5]
- NP_001124186.1 lymphoid enhancer-binding factor 1 isoform 3: "Transcript Variant: This variant (3) lacks both an in-frame exon in the central coding region and an exon in the 3' coding region that causes a frameshift, compared to variant 1. The encoded isoform (3) has a distinct C-terminus and is shorter than isoform 1."[5]
- NP_001159591.1 lymphoid enhancer-binding factor 1 isoform 4: "Transcript Variant: This variant (4) differs in the 5' UTR and 5' coding region, and lacks an alternate in-frame exon in the central coding region, compared to variant 1. The encoded isoform (4) has a distinct N-terminus and is shorter than isoform 1."[5]
- NP_057353.1 lymphoid enhancer-binding factor 1 isoform 1: "Transcript Variant: This variant (1) represents the longest transcript and encodes the longest isoform (1)."[5]
See also
References
- ↑ Gregory P. Copenhaver, Christopher D. Putnam, Michael L. Denton and Craig S. Pikaard (1994). "The RNA polymerase I transcription factor UBF is a sequence-tolerant HMG-box protein that can recognize structured nucleic acids" (PDF). Nucleic Acids Research. 22 (13): 2651–7. Retrieved 2017-04-05.
- ↑ Vincent Laudet, Dominique Stehelin and Hans Clevers (1993). "Ancestry and diversity of the HMG box superfamily" (PDF). Nucleic Acids Research. 21 (10): 2493–501. Retrieved 2017-04-05.
- ↑ 3.0 3.1 3.2 3.3 3.4 Marc van de Wetering, Mariette Oosterwegel, Klaske van Norren and Hans Clevers (1993). "Sox-4, an Sry-like HMG box protein, is a transcriptional activator in lymphocytes" (PDF). The EMBO Journal. 12 (10): .3847–3854. Retrieved 2017-02-13.
- ↑ Tomas Valenta, Jan Lukas, Vladimir Korinek (2003). "HMG box transcription factor TCF‐4's interaction with CtBP1 controls the expression of the Wnt target Axin2/Conductin in human embryonic kidney cells". Nucleic Acids Research. 31 (9): 2369–80. doi:10.1093/nar/gkg346. Retrieved 2017-04-05.
- ↑ 5.0 5.1 5.2 5.3 5.4 RefSeq (October 2009). "LEF1 lymphoid enhancer binding factor 1 [ Homo sapiens (human) ]". 8600 Rockville Pike, Bethesda MD, 20894 USA: National Center for Biotechnology Information, U.S. National Library of Medicine. Retrieved 5 April 2020.