C1D Human

C1D is a protein encoded by the C1D gene in humans. It is expressed in various tissues, including the kidney, heart, brain, spleen, lung, testis, liver, and small intestine . The recombinant form of C1D is often produced in E. coli and purified using conventional chromatography techniques .

1. RNA Processing: C1D is involved in the recruitment of the RNA exosome complex to pre-rRNA, mediating the 3’-5’ end processing of the 5.8S rRNA . This function is essential for maintaining RNA quality and stability, particularly at highly transcribed gene loci .

2. DNA Damage Response: C1D plays a significant role in the DNA damage response (DDR). It can activate PRKDC (DNA-dependent protein kinase) in the presence of both linear and supercoiled DNA . This activation is crucial for the repair of DNA double-strand breaks through non-homologous end joining and homologous recombination .

3. Apoptosis: C1D can induce apoptosis in a p53/TP53-dependent manner when DNA damage is beyond repair . This function helps in eliminating cells with severe genomic instability, thereby maintaining overall genomic integrity.

4. Chromatin Architecture: C1D is also involved in the regulation of chromatin architecture. It interacts with various proteins to modulate chromatin compaction, particularly at sites with repetitive sequences .

Research on C1D and its yeast homologues, such as Rrp47 (S. cerevisiae) and Cti1 (S. pombe), has highlighted its central role in coordinating RNA processing and DNA damage repair . The recombinant human C1D protein, often tagged with His or GST for purification, is widely used in research to study these processes.

Recombinant human C1D protein is typically stored at 4°C for short-term use and at -20°C for long-term storage. It is important to avoid freeze-thaw cycles to maintain its stability .