FXYD Proteins: New Tissue-Specific Regulators of the Ubiquitous Na,K-ATPase

Crambert, Gilles; Geering, Käthi

doi:10.1126/stke.2003.166.re1

Cited by 106 publications

(91 citation statements)

References 66 publications

(91 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2A, lanes 10 -12). As previously described (7), the Nt-3T/A mutant lacking the O-glycosylation sites Thr 3 , Thr 6 , and Thr 9 was degraded during a 48-h chase period (Fig. 2, A, lanes 4 -6, and C) indicating a role of O-glycosylation in the stability of FXYD7.…”

Section: Effects Of Mutations In the N-terminal Extracellular Domain supporting

confidence: 79%

“…This family contains 7 members that share a signature sequence consisting of the FXYD motif and 3 other conserved amino acid residues (for review see Ref. 6). We recently characterized FXYD7 (7), which is exclusively expressed in brain, both in neurons and glial cells.…”

mentioning

confidence: 99%

“…The iodinated antibody had an average specific activity of 5-20 ϫ 10 7 cpm/mol. The assay of binding to oocytes was performed 3,6, and 48 h after injection. Oocytes were incubated on ice for 1 h in MBS containing 10% heat-inactivated calf serum.…”

mentioning

confidence: 99%

See 2 more Smart Citations

FXYD7, Mapping of Functional Sites Involved in Endoplasmic Reticulum Export, Association With and Regulation of Na,K-ATPase

Crambert

Swee

et al. 2004

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

The brain-specific FXYD7 is a member of the recently defined FXYD family that associates with the ␣1-␤1 Na,K-ATPase isozyme and induces an about 2-fold decrease in its apparent K ؉ affinity. By using the Xenopus oocyte as an expression system, we have investigated the role of conserved and FXYD7-specific amino acids in the cellular routing of FXYD7 and in its association with and regulation of Na,K-ATPase. In contrast to FXYD2 and FXYD4, the studies on FXYD7 show that the conserved FXYD motif in the extracytoplasmic domain is not involved in the efficient association of FXYD7 with Na,K-ATPase. On the other hand, the conserved Gly 40 and Gly 29 , located on the same face of the transmembrane helix, were found to be implicated both in the association with and the regulation of Na,K-ATPase. Mutational analysis of FXYD7-specific regions revealed the presence of an ER export signal at the end of the cytoplasmic tail. Deletion of a C-terminal valine residue in FXYD7 significantly delayed and decreased its O-glycosylation processing and retarded the rate of its cell surface expression. This result indicates that the C-terminal valine residue is involved in the rapid and selective ER export of FXYD7, which could explain the observed post-translational association of FXYD7 with Na,KATPase. In conclusion, our study on FXYD7 provides new information on structural determinants of general importance for FXYD protein action. Moreover, FXYD7 is identified as a new member of proteins with a regulated ER export, which suggests that, among FXYD proteins, FXYD7 has a particular regulatory function in brain.

show abstract

Section: Effects Of Mutations In the N-terminal Extracellular Domain supporting

confidence: 79%

mentioning

confidence: 99%

See 1 more Smart Citation

FXYD7, Mapping of Functional Sites Involved in Endoplasmic Reticulum Export, Association With and Regulation of Na,K-ATPase

Crambert

Swee

et al. 2004

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…A major effect of FXYD proteins hitherto investigated relates to modulation of apparent Na ϩ or K ϩ affinities (19,20). A similar situation seems to exist for the PLMS/Na,K-ATPase system where PLMS truncation increases the apparent cytoplasmic Na ϩ affinity (Fig.…”

Section: Discussionmentioning

confidence: 77%

Regulation of Na,K-ATPase by PLMS, the Phospholemman-like Protein from Shark

Mahmmoud

Cramb

Maunsbach

et al. 2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

In Na,K-ATPase membrane preparations from shark rectal glands, we have previously identified an FXYD domain-containing protein, phospholemman-like protein from shark, PLMS. This protein was shown to associate and modulate shark Na,K-ATPase activity in vitro. Here we describe the complete coding sequence, expression, and cellular localization of PLMS in the rectal gland of the shark Squalus acanthias. The mature protein contained 74 amino acids, including the N-terminal FXYD motif and a C-terminal protein kinase multisite phosphorylation motif. The sequence is preceded by a 20 amino acid candidate cleavable signal sequence. Immunogold labeling of the Na,K-ATPase ␣-subunit and PLMS showed the presence of ␣ and PLMS in the basolateral membranes of the rectal gland cells and suggested their partial colocalization. Furthermore, through controlled proteolysis, the C terminus of PLMS containing the protein kinase phosphorylation domain can be specifically cleaved. Removal of this domain resulted in stimulation of maximal Na,K-ATPase activity, as well as several partial reactions. Both the E 1 ϳP 3 E 2 -P reaction, which is partially rate-limiting in shark, and the K ؉ deocclusion reaction, E 2 (K) 3 E 1 , are accelerated. The latter may explain the finding that the apparent Na ؉ affinity was increased by the specific C-terminal PLMS truncation. Thus, these data are consistent with a model where interaction of the phosphorylation domain of PLMS with the Na,K-ATPase ␣-subunit is important for the modulation of shark Na,K-ATPase activity.

show abstract

“…In this paper, the methods are described and illustrated with examples from the FXYD proteins, a family of tissue-specific and physiological-state-specific subunits of the Na,KATPase, that help to regulate the distribution of Na and K ion concentrations across animal cell membranes [17][18][19]. The FXYD protein sequences are highly conserved through evolution, and are characterized by a 35-amino acid FXYD homology domain, which includes the short signature motif PFXYD (Pro, Phe, X, Tyr, Asp) and the transmembrane domain (Fig.…”

Section: Introductionmentioning

confidence: 99%

NMR of membrane proteins in micelles and bilayers: The FXYD family proteins

Franzin

Gong

Thai

et al. 2007

Methods

View full text Add to dashboard Cite

Determining the atomic resolution structures of membrane proteins is of particular interest in contemporary structural biology. Helical membrane proteins constitute one-third of the expressed proteins encoded in a genome, many drugs have membrane-bound proteins as their receptors, and mutations in membrane proteins result in human diseases. Although integral membrane proteins provide daunting technical challenges for all methods of protein structure determination, nuclear magnetic resonance (NMR) spectroscopy can be an extremely versatile and powerful method for determining their structures and characterizing their dynamics, in lipid environments that closely mimic the cell membranes. Once milligram amounts of isotopically labeled protein are expressed and purified, micelle samples can be prepared for solution NMR analysis, and lipid bilayer samples can be prepared for solid-state NMR analysis. The two approaches are complementary and can provide detailed structural and dynamic information. This paper describes the steps for membrane protein structure determination using solution and solid-state NMR. The methods for protein expression and purification, sample preparation and NMR experiments are described and illustrated with examples from the FXYD proteins, a family of regulatory subunits of the Na, KATPase.

show abstract

FXYD Proteins: New Tissue-Specific Regulators of the Ubiquitous Na,K-ATPase

Cited by 106 publications

References 66 publications

FXYD7, Mapping of Functional Sites Involved in Endoplasmic Reticulum Export, Association With and Regulation of Na,K-ATPase

FXYD7, Mapping of Functional Sites Involved in Endoplasmic Reticulum Export, Association With and Regulation of Na,K-ATPase

Regulation of Na,K-ATPase by PLMS, the Phospholemman-like Protein from Shark

NMR of membrane proteins in micelles and bilayers: The FXYD family proteins

Contact Info

Product

Resources

About