Zfp263, also known as NT2, is a zinc finger protein containing a Krüppel-associated box (KRAB) domain. It functions as a transcriptional regulator and is likely involved in gene regulation pathways related to cartilage development. Understanding its function can be crucial for revealing the molecular mechanisms of skeletal morphogenesis, and genetic models like KO or CKO mouse models can provide valuable insights into its role.

NT2 was identified through screening a mouse limb bud cDNA expression library in the yeast one-hybrid system. It binds to a 24-bp sequence within the-530-bp promoter segment of the Col11a2 gene. In developing mouse cartilage, NT2 mRNA is highly expressed by hypertrophic chondrocytes but minimally expressed by resting and proliferating chondrocytes, inversely correlated with Col11a2 expression. Transfection of the NT2 expression vector in RSC cells (a chondrosarcoma cell line) inhibits Col11a2 promoter activity, while the mutant NT2 lacking the KRAB domain fails to do so, suggesting NT2 represses Col11a2 transcription [1].

In conclusion, Zfp263 (NT2) is a key negative regulator of Col11a2, playing an important role in the regulation of cartilage-specific expression of Col11a2. The use of cell-based models and potentially mouse models in these studies has revealed its function in cartilage development-related processes, which may be relevant to understanding skeletal morphogenesis-related diseases.