Disease relevance of LPXN

• In 81 patients with coronary atherosclerosis, with different number of affected coronary arteries determined by selective coronarography, the blood plasma levels of low-density (LDLP) and high-density (HDLP) lipoproteins were determined, and their lipid and protein components were analyzed [1].

High impact information on LPXN

• There are four carboxyl-terminal LIM domains in leupaxin that share 70% amino acid identity and 80% similarity with those in paxillin [2].
• We demonstrate here that leupaxin associates with a second FAK family member, PYK2 [2].
• We also demonstrate that leupaxin is a substrate for a tyrosine kinase in lymphoid cells and thus may function in and be regulated by tyrosine kinase activity [2].
• We have identified a novel cytoplasmic protein, leupaxin, that is preferentially expressed in hematopoietic cells and is most homologous to the focal adhesion protein, paxillin [2].
• Finally, in vitro inhibition of leupaxin expression in the osteoclast led to a decrease in resorptive capacity [3].

Biological context of LPXN

• In the current study, overexpression of LPXN in murine osteoclasts resulted in both enhanced resorptive activity and cell adhesion, as assessed by in vitro resorption assays [4].
• Overexpression of leupaxin by transduction into osteoclasts evoked numerous cytoplasmic projections at the leading edge of the cell, resembling a motile phenotype [3].

Anatomical context of LPXN

• Our data indicate that association of the scaffold protein LPXN with Src adds further complexity to the organization of the podosomal signaling complex in osteoclasts [4].
• As leupaxin and PYK2 are both preferentially expressed in leukocytes they may therefore form a cell type-specific signaling complex [2].
• Leupaxin can be detected in monocytes and osteoclasts, both cells of hematopoietic origin [3].

Associations of LPXN with chemical compounds

• Along with the increasing number of arteries affected the percentage of esterified cholesterol in the HDLP decreased, free cholesterol in the HDLP and esterified cholesterol in the LDLP rose [1].

Physical interactions of LPXN

• We could also demonstrate for the first time that leupaxin interacts with the androgen receptor in a ligand-dependent manner and serves as a transcriptional activator of this hormone receptor in PCa cells [5].

Other interactions of LPXN

• In the amino-terminal region of leupaxin there are three short stretches of approximately 13 amino acids that share 70-90% similarity with paxillin LD motifs [2].
• Leupaxin is expressed in cell types, such as macrophage, that lack FAK [2].
• After exposure to the pro-inflammatory and osteoclastogenic cytokine TNF-alpha, there was an increase in the level of Src that coimmunoprecipitated with LPXN [4].
• In an attempt to determine an additional biochemical basis for the observed phenomenon in increased osteoclast activity, a coimmunoprecipitation screen for additional binding partners revealed that Src, a protein tyrosine kinase that is critical to both podosome formation and osteoclast function, was also associated with LPXN [4].

References