The cullin7 E3 ubiquitin ligase: a novel player in growth control (Q37300974)

19 August 2017

1 reference

title

The cullin7 E3 ubiquitin ligase: a novel player in growth control (English)

1 reference

19 August 2017

Antonio Sarikas

1

1 reference

19 August 2017

Xinsong Xu

series ordinal

2

1 reference

19 August 2017

Loren J Field

series ordinal

3

1 reference

19 August 2017

Zhen-Qiang Pan

series ordinal

4

1 reference

19 August 2017

4 October 2008

1 reference

19 August 2017

8

1 reference

based on heuristic

inferred from page(s)

published in

Cell Cycle

1 reference

19 August 2017

7

1 reference

19 August 2017

3154-3161

1 reference

19 August 2017

20

1 reference

Chemokine signaling via the CXCR2 receptor reinforces senescence

19 August 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

The CUL7 E3 ubiquitin ligase targets insulin receptor substrate 1 for ubiquitin-dependent degradation

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Insulin-like growth factor I and II regulate the life cycle of trophoblast in the developing human placenta

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Ataxia telangiectasia-mutated damage-signaling kinase- and proteasome-dependent destruction of Mre11-Rad50-Nbs1 subunits in Simian virus 40-infected primate 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=2637179

The IGF axis and placental function. a mini review

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Disruption of the Fbxw8 gene results in pre- and postnatal growth retardation in mice

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Late effects of disturbed IGF signaling in congenital diseases

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Breaking news: high-speed race ends in arrest--how oncogenes induce senescence.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

CUL7 is a novel antiapoptotic oncogene

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Clinical, molecular and histopathological features of short stature syndrome with novel CUL7 mutation in Yakuts: new population isolate in Asia.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Induction of cullin 7 by DNA damage attenuates p53 function

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Molecular genetics of RecQ helicase disorders

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

The regulation of cyclin D1 degradation: roles in cancer development and the potential for therapeutic invention

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Insulin growth factor-binding protein 2 is a candidate biomarker for PTEN status and PI3K/Akt pathway activation in glioblastoma and prostate cancer

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

The conserved CPH domains of Cul7 and PARC are protein-protein interaction modules that bind the tetramerization domain of p53

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Oncogene-induced senescence pathways weave an intricate tapestry

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

A critical role for FBXW8 and MAPK in cyclin D1 degradation and cancer cell proliferation

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Phosphorylation-dependent ubiquitination of cyclin D1 by the SCF(FBX4-alphaB crystallin) complex

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Oncogene-induced cell senescence--halting on the road to cancer

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Fbxw8 is essential for Cul1-Cul7 complex formation and for placental development

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Cytoplasmic localized ubiquitin ligase cullin 7 binds to p53 and promotes cell growth by antagonizing p53 function.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Stops along the RAS pathway in human genetic disease

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Elevated circulating insulin-like growth factor binding protein-1 is sufficient to cause fetal growth 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=2637179

Identification of mutations in CUL7 in 3-M syndrome

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Crucial role of p53-dependent cellular senescence in suppression of Pten-deficient tumorigenesis

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

BRAFE600-associated senescence-like cell cycle arrest of human naevi

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Dimerization of CUL7 and PARC is not required for all CUL7 functions and mouse development

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Function and regulation of cullin-RING ubiquitin ligases

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Restraining PI3K: mTOR signalling goes back to the membrane.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Dysregulation of the TSC-mTOR pathway in human disease

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Tuberous sclerosis and insulin resistance. Unlikely bedfellows reveal a TORrid affair

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Absence of S6K1 protects against age- and diet-induced obesity while enhancing insulin sensitivity

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

The TSC1-2 tumor suppressor controls insulin-PI3K signaling via regulation of IRS proteins

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Nedd8 on cullin: building an expressway to protein destruction.

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Akt negatively regulates the in vitro lifespan of human endothelial cells via a p53/p21-dependent 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=2637179

Targeted disruption of p185/Cul7 gene results in abnormal vascular morphogenesis

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Human melanocyte senescence and melanoma susceptibility genes

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

CUL7: A DOC domain-containing cullin selectively binds Skp1.Fbx29 to form an SCF-like complex

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Cellular actions of the insulin-like growth factor binding proteins

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

High frequency of BRAF mutations in nevi

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

SOCS-1 and SOCS-3 block insulin signaling by ubiquitin-mediated degradation of IRS1 and IRS2

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

IRS proteins and the common path to diabetes

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

CUL-4A is critical for early embryonic development

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Enumeration of the simian virus 40 early region elements necessary for human cell transformation

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Loss of Cul1 results in early embryonic lethality and dysregulation of cyclin E

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Cullin-3 targets cyclin E for ubiquitination and controls S phase in mammalian 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=2637179

Characterization of the DOC1/APC10 subunit of the yeast and the human anaphase-promoting complex

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Oncogenic ras provokes premature cell senescence associated with accumulation of p53 and p16INK4a

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Role of insulin-like growth factors in embryonic and postnatal growth

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Mice carrying null mutations of the genes encoding insulin-like growth factor I (Igf-1) and type 1 IGF receptor (Igf1r)

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Signaling pathways: the benefits of good communication

6 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Expression of insulin-like growth factor binding protein-2 by MCF-7 breast cancer cells is regulated through the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway.

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Expression of a mutant p193/CUL7 molecule confers resistance to MG132- and etoposide-induced apoptosis independent of p53 or Parc binding

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Simian virus 40 large T antigen's association with the CUL7 SCF complex contributes to cellular transformation

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Simian virus 40 large T antigen stably complexes with a 185-kilodalton host protein

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Coexpression of mutant p53 and p193 renders embryonic stem cell-derived cardiomyocytes responsive to the growth-promoting activities of adenoviral E1A.

14 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Stimulation of insulin-like growth factor binding protein-1 synthesis by interleukin-1beta: requirement of the mitogen-activated protein kinase pathway

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

A rapamycin-sensitive pathway down-regulates insulin signaling via phosphorylation and proteasomal degradation of insulin receptor substrate-1.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

A variable degree of intrauterine and postnatal growth retardation in a family with a missense mutation in the insulin-like growth factor I receptor.

28 September 2017

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Homozygous and heterozygous expression of a novel insulin-like growth factor-I mutation

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Simian virus 40 large T antigen binds a novel Bcl-2 homology domain 3-containing proapoptosis protein in the cytoplasm.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Malignant melanoma: modern black plague and genetic black box.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

IGF-I is required for normal embryonic growth in mice

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

PARC and CUL7 form atypical cullin RING ligase complexes.

26 June 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Mutation at cleavage site of insulin-like growth factor receptor in a short-stature child born with intrauterine growth retardation.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Fetal growth restriction: a workshop report.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Inappropriate activation of the TSC/Rheb/mTOR/S6K cassette induces IRS1/2 depletion, insulin resistance, and cell survival deficiencies

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Expression of mutant p193 and p53 permits cardiomyocyte cell cycle reentry after myocardial infarction in transgenic mice

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

IGF-I receptor mutations resulting in intrauterine and postnatal growth retardation

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Akt1/PKBalpha is required for normal growth but dispensable for maintenance of glucose homeostasis in mice

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Size at birth and cord blood levels of insulin, insulin-like growth factor I (IGF-I), IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-3, and the soluble IGF-II/mannose-6-phosphate receptor in term human infants. The ALSPAC Study Team. Avon Longitudin

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Overexpression of insulin-like growth factor-binding protein-2 in transgenic mice reduces postnatal body weight gain.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Insulin resistance and growth retardation in mice lacking insulin receptor substrate-1.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Growth retardation and hyperglycemia in insulin-like growth factor binding protein-1 transgenic mice.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Insulin-like growth factors and their binding proteins in the term and preterm human fetus and neonate with normal and extremes of intrauterine growth.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Alternative pathway of insulin signalling in mice with targeted disruption of the IRS-1 gene.

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Shooting the Messenger: CULLIN' Insulin Signaling with Fbw8

2 September 2018

1 reference

https://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pmc&linkname=pmc_refs_pubmed&retmode=json&id=2637179

Deletion of the Cul1 gene in mice causes arrest in early embryogenesis and accumulation of cyclin E

3 December 2018

1 reference

PubMed

https://pubmed.ncbi.nlm.nih.gov/18927510

inferred from PubMed ID database lookup

12 December 2020

based on heuristic

IGF-I, IGF-II, free IGF-I and IGFBP-1, -2 and -3 levels in venous cord blood: relationship to birthweight, length and gestational age in healthy newborns

1 reference

PubMed

https://pubmed.ncbi.nlm.nih.gov/18927510

inferred from PubMed ID database lookup

12 December 2020

based on heuristic

Identifiers

DOI

10.4161/CC.7.20.6922

1 reference

19 August 2017

1 reference

19 August 2017

1 reference