Targeting of aminopeptidase n to bile canaliculi correlates with secretory activities of the developing canalicular domain

Lian, Wei-Nan; Tsai, Jin Wu; Yu, Pang-Mien; Wu, Tsan-Ming; Yang, Shun-Chun; Chau, Yat‐Pang; Lin, Chi‐Hung

doi:10.1002/hep.510300302

Cited by 24 publications

(19 citation statements)

References 64 publications

(102 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Live Cell Imaging-For calcium/sodium imaging, suspended cells were labeled either with 2 M Fluo-4 or with 2 M Sodium Green (Molecular Probes) at 37°C for 10 min before cell plating and observed under time lapse fluorescence microscopy (16,17). Fluorescence signals were quantified by MetaMorph program (Universal Imaging, Downingtown, PA).…”

Section: Methodsmentioning

confidence: 99%

Membrane Targeting and Coupling of NHE1-IntegrinαIIbβ3-NCX1 by Lipid Rafts following Integrin-Ligand Interactions Trigger Ca2+ Oscillations

Yi¹,

Ho²,

Chen³

et al. 2009

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

The cyclic calcium release and uptake during calcium oscillation are thought to result from calcium-induced calcium release (CICR); however, it is unclear, especially in nonexcitable cells, how the initial calcium mobilization that triggers CICR occurs. We report here a novel mechanism, other than conventional calcium channels or the phopholipase C-inositol trisphosphate system, for initiating calcium oscillation downstream of integrin signaling. Upon integrin ␣ IIb ␤ 3 binding to fibrinogen ligand or the disintegrin rhodostomin, sodium-proton exchanger NHE1 and sodiumcalcium exchanger NCX1 are actively transported to the plasma membrane, and they become physically coupled to integrin ␣ IIb ␤ 3 . Lipid raft-dependent mechanisms modulate the membrane targeting and formation of the NHE1-integrin ␣ IIb ␤ 3 -NCX1 protein complex. NHE1 and NCX1 within such protein complex are functionally coupled, such that a local increase of sodium concentration caused by NHE1 can drive NCX1 to generate sodium efflux in exchange for calcium influx. The resulting calcium increase inside the cell can then trigger CICR as a prelude to calcium oscillation downstream of integrin ␣ IIb ␤ 3 signaling. Fluorescence resonance energy transfer based on fluorescence lifetime measurements is employed here to monitor the intermolecular interactions among NHE1-integrin ␣ IIb ␤ 3 -NCX1, which could not be properly detected using conventional biochemical assays.In many excitable or nonexcitable cells, the concentration of free intracellular calcium oscillates with a period ranging from a few seconds to a few minutes. Such calcium oscillations are involved in a wide variety of cellular functions (1, 2). It is generally believed that, except for minor variations, the cyclic increase and decrease of calcium results from an autocatalytic release of calcium in a process called calcium-induced calcium release (CICR), 2 followed by a slow negative feedback that terminates calcium release. The cytoplasmic free calcium is then taken up into the organelles to reset the cycle. Despite a general agreement on how calcium oscillation proceeds once the system has been turned on, various different mechanisms have been proposed to explain how the initial calcium mobilization is generated that triggers CICR.As a general rule, calcium entry through voltage-gated channels in electrically excitable cells (3) or through agonist-receptor interactions in nonexcitable cells, such as epithelial cells, hepatocytes, or oocytes (4), is thought to initiate the CICR process (1, 2). Typically, in nonexcitable cells, the binding of an agonist, such as a hormone, a growth factor, or an extracellular matrix, to the corresponding cell surface receptor initiates a series of reactions that end in the activation of phopholipase C (PLC) and the production of the secondary messenger inositol trisphosphate (IP 3 ) (1, 2, 4). IP 3 is thought to induce calcium release from the internal endoplasmic reticulum or mitochondria store, and governs the CICR mechanisms that modulate calcium oscillat...

show abstract

Section: Methodsmentioning

confidence: 99%

Membrane Targeting and Coupling of NHE1-IntegrinαIIbβ3-NCX1 by Lipid Rafts following Integrin-Ligand Interactions Trigger Ca2+ Oscillations

Yi¹,

Ho²,

Chen³

et al. 2009

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…We have previously reported that Hep G2 cells cultured for 3 days form bile canaliculi (or the apical domain) that are characterized by a high concentrations of actin filaments in the microvilli (Lian et al, 1999). In these 'well-polarized' hepatic cells, membrane proteins were correctly transported to their specific membrane domains.…”

Section: Resultsmentioning

confidence: 99%

“…6B,C). Note that the control Hep G2 cells or cells expressing the wild-type Na dextran enters the bile canaliculi via permeable tight junctions in a process termed 'paracellular transport' (Lian et al, 1999). When applying these functional assays to the deglycosylation experiments (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The culture of the hepatoblastoma cell line, Hep G2 and immunofluorescence (IF) staining was according to methods described previously (Lian et al, 1999). The primary antibodies included those made against FLAG M2 and ␣-tubulin (from Sigma), Na + /K + -ATPase ␣-subunit (from Affinity Bioreagents), Na + /K + -ATPase ␤-subunit and CD147 (from BD Bioscience), calreticulin (ER marker, from Abcam, Cambridge, UK).…”

Section: Cell Culture and Immunofluorescence Stainingmentioning

confidence: 99%

“…The resulting immunoprecipitates were separated by 10.5% SDS-PAGE and transfected to a nitrocellulose membrane (Bio-Rad). After confirmation of the presence of proteins by Ponceau-S staining, standard western blotting procedures were performed (Lian et al, 1999). The blotting signal was detected by SuperSignal Chemiluminescent substrate (Pierce) and recorded by Hyperfilm (Amersham-Pharmacia).…”

Section: Immunoprecipitation and Western Blot Analysismentioning

confidence: 99%

See 2 more Smart Citations

Deglycosylation of Na+/K+-ATPase causes the basolateral protein to undergo apical targeting in polarized hepatic cells

Lian¹,

Wu²,

Dao³

et al. 2006

Journal of Cell Science

Self Cite

View full text Add to dashboard Cite

Polarized epithelia, such as hepatocytes, target their integral membrane proteins to specific apical or basolateral membrane domains during or after biogenesis. The roles played by protein glycosylation in this sorting process remain controversial. We report here that deglycosylation treatments in well-polarized hepatic cells by deglycosylation drugs, or by site-directed mutagenesis of the N-linked-glycosylation residues, all cause the Na+/K+-ATPase β-subunit to traffic from the native basolateral to the apical/canalicular domain. Deglycosylated β-subunits are still able to bind and therefore transport the catalytic α-subunits to the aberrant apical location. Such apical targeting is mediated via the indirect transcytosis pathway. Cells containing apical Na+/K+-ATPase appear to be defective in maintaining the ionic gradient across the plasma membrane and in executing hepatic activities that are dependent upon the ionic homeostasis such as canalicular excretion.

show abstract

CD13

Riemann

2002

Wiley Encyclopedia of Molecular Medicine

View full text Add to dashboard Cite

Targeting of aminopeptidase n to bile canaliculi correlates with secretory activities of the developing canalicular domain

Cited by 24 publications

References 64 publications

Membrane Targeting and Coupling of NHE1-IntegrinαIIbβ3-NCX1 by Lipid Rafts following Integrin-Ligand Interactions Trigger Ca2+ Oscillations

Membrane Targeting and Coupling of NHE1-IntegrinαIIbβ3-NCX1 by Lipid Rafts following Integrin-Ligand Interactions Trigger Ca2+ Oscillations

Deglycosylation of Na+/K+-ATPase causes the basolateral protein to undergo apical targeting in polarized hepatic cells

CD13

Contact Info

Product

Resources

About