Hyaluronan or hyaluronic acid (HA) is a high molecular weight unbranched polysaccharide synthesized by a wide variety of organisms from bacteria to mammals, and is a constituent of the extracellular matrix. It consists of alternating glucuronic acid and N-acetylglucosamine residues that are linked by beta-1-3 and beta-1-4 glycosidic bonds. HA is synthesized by membrane-bound synthase at the inner surface of the plasma membrane, and the chains are extruded through pore-like structures into the extracellular space. It serves a variety of functions, including space filling, lubrication of joints, and provision of a matrix through which cells can migrate. HA is actively produced during wound healing and tissue repair to provide a framework for ingrowth of blood vessels and fibroblasts. Changes in the serum concentration of HA are associated with inflammatory and degenerative arthropathies such as rheumatoid arthritis. In addition, the interaction of HA with the leukocyte receptor CD44 is important in tissue-specific homing by leukocytes, and overexpression of HA receptors has been correlated with tumor metastasis. HAS2 is a member of the newly identified vertebrate gene family encoding putative hyaluronan synthases, and its amino acid sequence shows significant homology to glycosaminoglycan synthetase (DG42) from Xenopus laevis, and human and murine hyaluronan synthase 1. [provided by RefSeq, Jul 2008]
Transcription factors with Perturb-seq knockdown data for HAS2. The Binding column indicates whether any binding evidence exists for this TF–gene pair (ChIP-seq or motif footprint peaks). The Mean coef is the average Perturb-seq regression coefficient across active gRNAs (positive = HAS2 upregulated upon KD; negative = downregulated). The Outlier column indicates whether this gene is in the top or bottom 5% of all TF knockdown effects.
| TF | Mean coef | Binding | Outlier | TF→Gene link |
|---|
Open chromatin peaks (ATAC-seq) in the genomic neighbourhood of HAS2, linked by TSS proximity or chromatin conformation (Multiome / HiCAR). Each element overlaps at least one TF ChIP-seq binding site — the TFs column shows how many distinct TFs bind that element.
| Accessibility | Element | Dist. to TSS | Link type | TFs |
|---|---|---|---|---|
| chr8:121,537,980–121,538,930 | 103.0 kb | Distal (>10kb) Multiome | 126 | |
| chr8:121,638,932–121,640,661 | 2.0 kb | Proximal (<10kb) Multiome | 560 | |
| chr8:121,641,223–121,643,313 | 125 bp | At TSS Multiome | 595 | |
| chr8:121,649,623–121,650,787 | 8.5 kb | Proximal (<10kb) Multiome | 168 | |
| chr8:121,669,074–121,670,012 | 28.2 kb | Distal (>10kb) Multiome | 271 | |
| chr8:121,741,843–121,742,567 | 100.6 kb | Distal (>10kb) Multiome | 238 | |
| chr8:121,756,389–121,757,302 | 115.3 kb | Distal (>10kb) Multiome | 82 | |
| chr8:121,818,237–121,819,660 | 177.9 kb | Distal (>10kb) Multiome | 237 | |
| chr8:121,821,066–121,822,156 | 180.1 kb | Distal (>10kb) Multiome HiCAR | 214 | |
| chr8:122,079,024–122,080,313 | 438.5 kb | Distal (>10kb) Multiome HiCAR | 205 | |
| chr8:122,638,668–122,639,514 | 997.6 kb | Distal (>10kb) Multiome HiCAR | 424 |
Genomic view of the HAS2 locus showing ATAC-seq accessibility and RNA-seq expression across the ESC → DE time course, together with TF binding peaks and element-to-TSS loop connections.