Page 11 - GPD-3-3

Gene & Protein in Disease Comprehensive analysis of ZNF521/Zfp521

Furthermore, Zfp521 can undergo ubiquitination PTHrP regulate its expression. As a downstream factor
55
(Figure 3). In this process, EBF1 increases the ubiquitination of PTHR1, PTHrP can regulate chondrocyte maturation
of Zfp521, mediated by SIAH2. The ubiquitousness level of and the regulation of Zfp521 expression. Zfp521 acts as
19
Zfp521 decreases when SIAH2 is without ligase, indicating a downstream effector of PTHR1 signaling, controlling
that the interaction between Zfp521 and EBF1 decreases the proliferation, differentiation, and cell death of
the Zfp521 level by increasing the ubiquitin-dependent chondrocytes. 9,19,56,57 RUNX2 is an important regulator
proteasome degradation mediated by SIAH2. 50 of osteoblast commitment and early stages of osteoblast
differentiation, and RUNX2 is a key regulator downstream
3.2. Interacting protein of ZNF521/Zfp521 of BMPs and PTHrP. Zfp521 associates with RUNX2
2
Numerous proteins interacting with ZNF521 have and antagonizes its activity by an HDAC4-dependent
been found. It is increasingly clear that the tumor mechanism. HDAC4 is required for Zfp521-mediated
1,23
inhibitory effect of ZNF521 can be controlled by its inhibition of RUNX2 activity in chondrocytes. HDAC4
binding partners. 5,8,15,23,28,38 Protein–protein interactions binds to and antagonizes RUNX2 in pre-hypertrophic
may help control ZNF521 activity during normal chondrocytes. However, the depletion of HDAC4 attenuates
development. 19,20,22,24,37 Zfp521-induced inhibition of RUNX2. In the absence of
Zfp521 is the lineage determinant of MSCs. It boosts Zfp521, PTHrP fails to counteract RUNX2, underscoring
osteogenesis but restrains adipogenesis through complex Zfp521’s significance as a target gene for PTHrP-mediated
physical and functional interaction networks with Zfp423, regulation of chondrocyte proliferation and differentiation
19
EBF1, and RUNX2, combined with the contributions of in the growth plate. In chondrocytes, Zfp521 deficiency
various chromatin remodeling factors. 8,51 leads to reduced chondrocyte proliferation, increased
chondrocyte differentiation, and cell death during growth
In addition, the activation of early neural genes plate development in mice. PTHrP can delay chondrocyte
56
promotes the spontaneous transformation of ectodermal hypertrophy , and deletion of Zfp521 from chondrocytes
58
cells into neural ectodermal progenitor cells, which can partially repair the defects in hypertrophic chondrocyte
requires the interaction between Zfp521 and coactivator differentiation and then repair the endochondral bone
P300. Zfp521 induces the expression of many early formation. One reason for this is that RUNX2 activity is
5,21
neural genes, including SOX1, SOX3, and PAX6, through increased in the Zfp521-deficient chondrocytes, which
its N-terminal zinc finger motif and P300 activator. 5,16,20 leads to accelerated chondrocyte differentiation. 56,58 Osterix
The intrinsic histone acetyltransferase (HAT) activity (Osx) is a downstream target of RUNX2, and the silencing
59
of the P300 coactivator on the nerve gene and the of the Osx gene in mouse chondrocyte ATDC5 cells leads
co-inhibition of the histone deacetylase (NuRD) complex to the down regulation of chondrocyte marker expression
on some non-nerve-determinant genes, such as RUNX2 or and a reduction in chondrocyte differentiation. 57
SOX9, through the interaction with Zfp521, elucidate the
main mechanism of nerve induction of Zfp52. 15,21,51,52 The This process is relevant to the development of
co-localization of Zfp521 and p300 in the neuroectodermal osteoarthritis (OA). Osteoarthritis is a damaging joint
gene locus is not a coincidence, and there is also a physical disease, characterized by cartilage degeneration, bone
correlation between Zfp521 and P300. P300-mediated sclerosis, and persistent low-grade inflammation in the
21
neutralization was not observed in Zfp521-depleted ES joints. 60,61 Extracellular matrix (ECM) degradation is
61
cells, suggesting that p300 requires Zfp521 to promote considered a hallmark of OA. Chondrocytes, which
neural differentiation. 5,6,20,21 are an important component of cartilage, play a critical
role in maintaining anabolic and catabolic balance by
ZNF521 also interacts with SIAH2, thereby participating 61,62
in BMP4-stimulated adipogenesis in adipose tissue. 50,53,54 synthesizing ECM. Zfp521 has an important regulatory
19
In addition, it also participates in the formation of SIAH2, role in chondrocyte homeostasis and maintains ECM
61
EBF1, and Zfp521 complexes, thereby enhancing the homeostasis through chondroprotective effects.
SIAH2-mediated ubiquitousness and degradation of In fat-derived stem cells, ZNF521 inhibits the generation
Zfp521 and increasing the level of EBF1. 50 of mature adipocytes. The silencing of ZNF521 significantly
enhances the adipogenic differentiation of hADSCs. ZNF521
3.3. Upstream and downstream factors of ZNF521/ is a key negative regulator of hADSCs. The inhibition of
23
Zfp521 lipogenesis by ZNF521 is due to the inhibition of EBF1,
Zfp521 is a downstream target gene of the PTHrP, PTHR1, which is a transcription factor required for generating
and cAMP signaling pathways. Its expression increases adipocyte progenitors. EBF1 promotes lipogenesis by
during osteoblast differentiation in vitro, while BMPs and inducing the expression of PPARγ and C/EBPα. 63-65 ZFP423

Volume 3 Issue 3 (2024) 5 doi: 10.36922/gpd.3260