FXYD5 Human

FXYD5 consists of 178 amino acid residues and is expressed in a variety of epithelial tissues. It is particularly abundant in the intestine, spleen, lung, and kidney, with lower expression levels in muscle tissues . The protein is also present in endothelial cells and lymphocytes, although its physiological significance in the lymphatic system remains to be fully understood .

FXYD5 acts as an auxiliary subunit of the Na+/K±ATPase, a crucial enzyme responsible for maintaining the electrochemical gradients of sodium and potassium ions across the plasma membrane . This regulation is essential for various cellular processes, including cell volume control, nutrient uptake, and electrical excitability.

One of the notable functions of FXYD5 is its involvement in modulating cellular junctions and influencing chemokine production . It affects cell adhesion by down-regulating E-cadherin, a protein that plays a critical role in maintaining cell-cell adhesion and tissue integrity . This down-regulation is particularly significant in the context of tumor development and metastasis, as it can lead to increased tumor cell motility and invasiveness .

FXYD5 has been identified as a cancer-associated cell membrane glycoprotein. Enhanced expression of FXYD5 has been correlated with tumor progression in various types of cancer . The protein was initially identified as a cell surface molecule by a monoclonal antibody developed to selectively recognize cancerous cells . Due to its effect of reducing cell-cell adhesion in transfected liver cancer cells, it was termed Dysadherin .

Recombinant human FXYD5 protein, fused to a His-tag at the N-terminus, is expressed in Escherichia coli and purified using conventional chromatography techniques . This recombinant protein is used in research to study the functional effects of FXYD5 and its role in various cellular processes.