(Q37417281)

20 August 2017

Mechanoregulation of BK channel activity in the mammalian cortical collecting duct: role of protein kinases A and C. (English)

1 reference

20 August 2017

Wen Liu

1

1 reference

20 August 2017

Yuan Wei

2

1 reference

20 August 2017

Peng Sun

3

1 reference

20 August 2017

Wen-Hui Wang

4

1 reference

20 August 2017

Thomas R Kleyman

5

1 reference

20 August 2017

Lisa M Satlin

6

1 reference

20 August 2017

5 August 2009

1 reference

American Journal of Physiology - Renal Physiology

20 August 2017

1 reference

20 August 2017

297

1 reference

20 August 2017

4

1 reference

20 August 2017

F904-15

1 reference

Epoxyeicosatrienoic acid activates BK channels in the cortical collecting duct

20 August 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Effect of aldosterone on BK channel expression in mammalian cortical collecting duct

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Alkaline pH- and cAMP-induced V-ATPase membrane accumulation is mediated by protein kinase A in epididymal clear cells

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Phorbol ester stimulation of RasGRP1 regulates the sodium-chloride cotransporter by a PKC-independent pathway.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Angiotensin II inhibits the ROMK-like small conductance K channel in renal cortical collecting duct during dietary potassium restriction

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Inhibition of MAPK stimulates the Ca2+ -dependent big-conductance K channels in cortical collecting duct

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

A common mechanism underlies stretch activation and receptor activation of TRPC6 channels

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Regulation of cation transport in the distal nephron by mechanical forces

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

BK channels in the kidney: role in K(+) secretion and localization of molecular components

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

MaxiK channel partners: physiological impact

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Distinct stoichiometry of BKCa channel tetramer phosphorylation specifies channel activation and inhibition by cAMP-dependent protein kinase.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Non-kinase second-messenger signaling: new pathways with new promise

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Immunolocalization of protein kinase C isoenzymes alpha, beta I, beta II, delta, and epsilon in mouse kidney.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Polycystins 1 and 2 mediate mechanosensation in the primary cilium of kidney cells

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Pathways that control cortical F-actin dynamics during secretion

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Coupling of c-Src to large conductance voltage- and Ca2+-activated K+ channels as a new mechanism of agonist-induced vasoconstriction

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Novel "nonkinase" phorbol ester receptors: the C1 domain connection

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Sequential activation of protein kinase C (PKC)-alpha and PKC-epsilon contributes to sustained Raf/ERK1/2 activation in endothelial cells under mechanical strain

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Immunolocalization of protein kinase C isoenzymes alpha, beta1 and betaII in rat kidney.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Regulation of RasGRP via a phorbol ester-responsive C1 domain.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Protein kinase A activity is required for the budding of constitutive transport vesicles from the trans-Golgi network

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Taxonomy and function of C1 protein kinase C homology domains

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Protein kinase C mu is located at the Golgi compartment

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Phenotypic alteration of a human BK (hSlo) channel by hSlobeta subunit coexpression: changes in blocker sensitivity, activation/relaxation and inactivation kinetics, and protein kinase A modulation

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Rottlerin, a novel protein kinase inhibitor

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Functional role of the beta subunit of high conductance calcium-activated potassium channels

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Effects of protein kinase C activation on sodium, potassium, chloride, and total CO2 transport in the rabbit cortical collecting tubule

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Dual modulation of renal ATP-sensitive K+ channel by protein kinases A and C.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

The bisindolylmaleimide GF 109203X is a potent and selective inhibitor of protein kinase C

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Purification and characterization of a unique, potent, peptidyl probe for the high conductance calcium-activated potassium channel from venom of the scorpion Buthus tamulus

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Reversible tyrosine protein phosphorylation regulates large conductance voltage- and calcium-activated potassium channels via cortactin

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Vasopressin-induced membrane trafficking of TRPC3 and AQP2 channels in cells of the rat renal collecting duct

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Dual role of the TRPV4 channel as a sensor of flow and osmolality in renal epithelial cells

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Potent stimulation of large-conductance Ca2+-activated K+ channels by rottlerin, an inhibitor of protein kinase C-delta, in pituitary tumor (GH3) cells and in cortical neuronal (HCN-1A) cells

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Temperature-modulated diversity of TRPV4 channel gating: activation by physical stresses and phorbol ester derivatives through protein kinase C-dependent and -independent pathways

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Modulation of ion channels by protein phosphorylation and dephosphorylation

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Alternative splicing determines sensitivity of murine calcium-activated potassium channels to glucocorticoids.

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Neurotrophin-3 inhibits HCO absorption via a cAMP-dependent pathway in renal thick ascending limb

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

A molecular switch for specific stimulation of the BKCa channel by cGMP and cAMP kinase

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

CalDAG-GEFIII activation of Ras, R-ras, and Rap1.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Simultaneous binding of two protein kinases to a calcium-dependent potassium channel.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Glucocorticoid regulation of calcium-activated potassium channels mediated by serine/threonine protein phosphatase.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Glucocorticoids block protein kinase A inhibition of calcium-activated potassium channels

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Regulation of large calcium-activated potassium channels by protein phosphatase 2A.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Mechanism of activation by cGMP-dependent protein kinase of large Ca(2+)-activated K+ channels in mesangial cells.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Selective inhibition of protein kinase C isozymes by the indolocarbazole Gö 6976.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Low-conductance K channels in apical membrane of rat cortical collecting tubule.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Effects of luminal Na+ on single Na+ channels in A6 cells, a regulatory role for protein kinase C.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Apical maxi K channels in intercalated cells of CCT.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

A Component of Calcium-activated Potassium Channels Encoded by the Drosophila slo Locus

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Somatostatin stimulates Ca2+-activated K+ channels through protein dephosphorylation

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Apical and basolateral effects of PTH in OK cells: transport inhibition, messenger production, effects of pertussis toxin, and interaction with a PTH analog

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Regulation of Ca(2+)-activated K+ channels by protein kinase A and phosphatase inhibitors

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Identification and localization of BK-beta subunits in the distal nephron of the mouse kidney.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Renal expression of osmotically responsive cation channel TRPV4 is restricted to water-impermeant nephron segments

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

PKC activates BKCa channels in rat pulmonary arterial smooth muscle via cGMP-dependent protein kinase

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Protein kinase C inhibits BKCachannel activity in pulmonary arterial smooth muscle

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Beta 1-subunits are required for regulation of coupling between Ca2+ transients and Ca2+-activated K+ (BK) channels by protein kinase C.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Effect of flow and stretch on the [Ca2+]i response of principal and intercalated cells in cortical collecting duct

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Effects of luminal flow and nucleotides on [Ca(2+)](i) in rabbit cortical collecting duct

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Epithelial Na(+) channels are regulated by flow

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Flow-dependent activation of maxi K+ channels in apical membrane of rabbit connecting tubule

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Slob, a novel protein that interacts with the Slowpoke calcium-dependent potassium channel

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

dSLo interacting protein 1, a novel protein that interacts with large-conductance calcium-activated potassium channels.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Apical K+ conductance in maturing rabbit principal cell.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Functional differences among alternatively spliced variants of Slowpoke, a Drosophila calcium-activated potassium channel.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Chromaffin cell cortical actin network dynamics control the size of the release-ready vesicle pool and the initial rate of exocytosis

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Flow-dependent potassium secretion by rabbit cortical collecting tubule in vitro

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2775580

Characterization of the interaction of a protein inhibitor with adenosine 3',5'-monophosphate-dependent protein kinases. I. Interaction with the catalytic subunit of the protein kinase

2 September 2018

1 reference

12 December 2020

Potassium secretion by cortical collecting tubule: relation to sodium absorption, luminal sodium concentration, and transepithelial voltage

1 reference

12 December 2020

Flow dependence of K+ secretion in cortical distal tubules of the rat

1 reference

12 December 2020

Ca2+ dependence of flow-stimulated K secretion in the mammalian cortical collecting duct

1 reference

12 December 2020

Membrane receptor location defines receptor interaction with signaling proteins in a polarized epithelium

1 reference

12 December 2020

Protein kinase A anchoring proteins are required for vasopressin-mediated translocation of aquaporin-2 into cell membranes of renal principal cells

1 reference

12 December 2020

Identification of the major site of in vitro PKA phosphorylation in the polycystin-1 C-terminal cytosolic domain

1 reference

12 December 2020

Maxi-K channels contribute to urinary potassium excretion in the ROMK-deficient mouse model of Type II Bartter's syndrome and in adaptation to a high-K diet

1 reference

12 December 2020

Strain-induced fetal type II epithelial cell differentiation is mediated via cAMP-PKA-dependent signaling pathway

1 reference

12 December 2020

TRPV4 as a flow sensor in flow-dependent K+ secretion from the cortical collecting duct

1 reference

12 December 2020

High-conductance K channels in intercalated cells of the rat distal nephron

1 reference

12 December 2020

The PKD1 gene product, "polycystin-1," is a tyrosine-phosphorylated protein that colocalizes with alpha2beta1-integrin in focal clusters in adherent renal epithelia

1 reference

12 December 2020

Conditional and unconditional inhibition of calcium-activated potassium channels by reversible protein phosphorylation

1 reference

12 December 2020

Luminal and contraluminal action of 1-34 and 3-34 PTH peptides on renal type IIa Na-P(i) cotransporter

1 reference

12 December 2020

Enhanced activity of a large conductance, calcium-sensitive K+ channel in the presence of Src tyrosine kinase

1 reference

12 December 2020

Alternative splicing switches potassium channel sensitivity to protein phosphorylation

1 reference

12 December 2020

Protein kinase C-dependent phosphorylation of synaptosome-associated protein of 25 kDa at Ser187 potentiates vesicle recruitment

1 reference

12 December 2020

Postnatal maturation of potassium transport in rabbit cortical collecting duct

1 reference

12 December 2020

Kinase and phosphatase activities intimately associated with a reconstituted calcium-dependent potassium channel

1 reference

12 December 2020

Activation of protein kinase C inhibits calcium-activated potassium channels in rat pituitary tumour cells

1 reference

12 December 2020

Ontogeny of flow-stimulated potassium secretion in rabbit cortical collecting duct: functional and molecular aspects

1 reference

12 December 2020

10.1152/AJPRENAL.90685.2008

Identifiers

DOI

1 reference

release_wrbjh252svftjn4cq3wo72upmu

20 August 2017

1 reference

Fatcat

https://api.fatcat.wiki/v0/release/wrbjh252svftjn4cq3wo72upmu

24 November 2022

mapped directly with Wikidata item

1 reference

20 August 2017

PubMed publication ID

19656909

1 reference