High impact information on EPB41L2

• We have identified a novel generally expressed homologue of the erythrocyte membrane cytoskeletal protein 4.1, named 4.1G, based on the interaction of its COOH-terminal domain (CTD) with the immunophilin FKBP13 [1].
• We also found that 4.1G, a ubiquitous homolog of 4.1R, is present in mutated as well as control cells and that its C-terminal region binds efficiently to NuMA, suggesting that in fact mitotic spindles host a mixture of the two 4.1 family members [2].
• These findings led to the postulate that the coexpression at the spindle poles of 2 related proteins, 4.1R and 4.1G, might reflect a functional redundancy in mitotic cells [2].
• We show that the carboxyl-terminal peptide of PTA-1 also can bind human discs large and that the presence or absence of this peptide greatly influences binding between PTA-1 and different isoforms of 4.1G [3].
• This was due to a decrease in the ability of 4.1G and 4.1B SAB domain to interact with actin but not with spectrin [4].

Biological context of EPB41L2

• In this paper we report evidence for a second 4.1 gene, 4.1G (HGMW-approved symbol EPB41L2), which maps to human chromosome 6q23 and is widely expressed among human tissues [5].
• The complete nucleotide sequence of 4.1G cDNA predicts a 113-kDa protein that exhibits three regions of high homology to 4.1R, including the membrane binding domain, the spectrinactin binding domain, and the C-terminal domain [5].
• Studies in HEK-293 (human embryonic kidney 293) cells and Chinese-hamster ovary cells showed that 4.1G interfered with A1AR signal transduction, as 4.1G reduced A1AR-mediated inhibition of cAMP accumulation and intracellular calcium release [6].
• The phosphorylation was enhanced by the expression of 4.1G, but not 4.1G-CTD [7].

Anatomical context of EPB41L2

• The present study investigated the expression and distributions of 4.1G in rodent sciatic nerve [8].
• Expression of protein 4.1G in Schwann cells of the peripheral nervous system [8].
• These data support the concept that 4.1G plays an important role in the membrane expansion and specialization that occurs during formation and maintenance of myelin internodes in the peripheral nervous system [8].
• Immunohistochemical study revealed that both PTHR and 4.1G were co-localized on plasma membranes, when they were transiently expressed in COS-7 cells [7].

Associations of EPB41L2 with chemical compounds

• These observations identify 4.1G as a novel A1AR-binding partner that can regulate adenosine action [6].
• Cytoskeletal protein 4.1G is a binding partner of the metabotropic glutamate receptor subtype 1 alpha [9].

Other interactions of EPB41L2

• Thus, 4.1N, 4.1B and 4.1G all show high accumulation in nervous tissues. mRNA for betaIISigma2-spectrin is ubiquitous, but most abundant in cardiac and nervous tissues [10].

Analytical, diagnostic and therapeutic context of EPB41L2

• Northern and Western blot analysis detected abundant 4.1G mRNA and protein in rat sciatic nerve extracts [8].
• Immunoelectron microscopy confirmed the immunodistribution of 4.1G in Schwann cells [8].

References