MGSSHHHHHH SSGLVPRGSH MKPTEKKDRV HHEPQLSDKV HNDAQSFDYD HDAFLGAEEA KTFDQLTPEE SKERLGKIVS KIDGDKDGFV TVDELKDWIK FAQKRWIYED VERQWKGHDL NEDGLVSWEE YKNATYGYVL DDPDPDDGFN YKQMMVRDER RFKMADKDGD LIATKEEFTA FLHPEEYDYM KDIVVQETME DIDKNADGFI DLEEYIGDMY SHDGNTDEPE WVKTEREQFV EFRDKNRDGK MDKEETKDWI LPSDYDHAEA EARHLVYESD QNKDGKLTKE EIVDKYDLFV GSQATDFGEA LVRHDEF.
Recombinant human calumenin, particularly the variant with a His tag, is produced using mammalian expression systems, such as HEK 293 cells . This recombinant protein typically has a high purity level, often exceeding 90% as determined by SDS-PAGE . The His tag, usually located at the C-terminus, facilitates purification and detection of the protein .
The recombinant human calumenin protein consists of 303 amino acids and has a predicted molecular mass of approximately 35.9 kDa. However, it migrates as a band of around 46-52 kDa in SDS-PAGE under reducing conditions .
Calumenin plays a crucial role in the calcium homeostasis within the ER. It contributes to the regulation of calcium levels, which is essential for various cellular functions, including muscle contraction, enzyme activity, and signal transduction . Additionally, calumenin is involved in the quality control of protein folding and sorting within the ER, ensuring that only properly folded proteins are transported to their final destinations .