CHP Human

Calcium Binding Protein P22 is a full-length protein consisting of 195 amino acids. It is expressed in Escherichia coli and has a purity of over 95%, making it suitable for various applications such as SDS-PAGE and mass spectrometry (MS) . The protein includes an N-terminal His-tag, which facilitates its purification and detection in experimental settings .

1. Regulation of Vesicular Trafficking: Calcium Binding Protein P22 is involved in the regulation of vesicular trafficking, particularly in the constitutive exocytic membrane traffic. It mediates the association between microtubules and membrane-bound organelles of the endoplasmic reticulum and Golgi apparatus .

2. Plasma Membrane Na+/H+ Exchanger: This protein functions as an integral cofactor in cell pH regulation by controlling the activity of the plasma membrane-type Na+/H+ exchanger (NHE). It affects the pH sensitivity of SLC9A1/NHE1 by increasing its sensitivity at acidic pH, thereby stabilizing and localizing SLC9A1/NHE1 at the plasma membrane .

3. Gene Transcription: Calcium Binding Protein P22 also plays a role in gene transcription. It acts as an inhibitor of ribosomal RNA transcription by repressing the nucleolar UBF1 transcriptional activity. This inhibition may involve sequestering UBF1 in the nucleoplasm and limiting its translocation to the nucleolus .

4. Inhibition of Calcineurin Activity: The protein has sequence similarity to calcineurin B and is known to be an endogenous inhibitor of calcineurin activity. This inhibition is crucial for maintaining cellular homeostasis and regulating various signaling pathways .

Due to its high purity and specific binding properties, recombinant Calcium Binding Protein P22 is widely used in research to study calcium signaling, vesicular trafficking, and pH regulation. It is also utilized in high-throughput screening assays and other biochemical applications .