DDR1 (CD167a)
Author: Wolfgang Vogel
Reviewer: Hans-Joerg Buehring
PROW 1:41-46(2000)

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OVERVIEW Summary Sentence

• DDR1 (CD167a) is a receptor tyrosine kinase (RTK) widely expressed in normal and transformed epithelial cells and is activated by various types of collagen

Abstract

• DDR1 belongs to a subfamily of tyrosine kinase receptors with a homology region to the Dictyostelium discoideum protein discoidin I in their extracellular domain. So far, two members have been identified, discoidin domain receptor 1 and 2 (DDR1 and DDR2). During the cell aggregation of Dictyostelium, discoidin I is secreted, functions as a lectin and is thought to be important in maintenance of morphology, cytoskeletal organization, and the ability to align with other cells during aggregation. The discoidin domain in the extracellular regions of both, DDR1 and DDR2, are thought to play a role in cell-cell contact and in cell adhesion signaling pathways
• Various types of collagen have been identified as the cognate ligands for both DDRs. Whereas DDR1 autophosphorylation is achieved by all collagens so far tested (type I to type VI), DDR2 is only activated by fibrillar collagens, in particular by collagen type I and type III. In contrast to most other tyrosine kinase receptors, DDR activation follows very slow kinetics, requiring up to 18 hours to reach maximal kinase activity. The presence of the discoidin domain in DDR is thought to be essential for collagen binding. DDR1 activation takes place in the absence of a functional beta1 integrin receptor for collagen
• cDNAs coding for DDR1 have been cloned from several human carcinoma cells, and from placenta and keratinocytes. Genes homologous to human DDR1 have been identified in mouse, rat and Caenorhabditis elegans. In situ studies and Northern-blot analysis showed that expression of human DDR1 is restricted to epithelial cells, particularly in the kidney, lung, gastrointestinal tract, and brain. In addition, DDR1 is significantly over-expressed in several human tumors from breast, ovarian, esophageal, and pediatric brain
• Human DDR1 is located on chromosome 6p21.3 in proximity to several HLA class I genes. Mouse DDR1 is located on chromosome 17C. The human gene is composed of 17 exons; the extracellular domain is encoded by 8 exons, three of which encode the discoidin domain. One exon encodes the transmembrane region, three the juxtamembrane domain, and five the catalytic domain. Compared to other RTK, the juxtamembrane region of DDR1 is significantly longer (176 amino acids). DDR1 is partially processed into a 63 kDa membrane-anchored beta-subunit and a 54 kDa soluble, extracellular domain-containing alpha-subunit, by a yet unidentified protease. So far, three isoforms of DDR1 generated by alternative splicing, were identified: DDR1a, DDR1b and DDR1c. The longest transcript codes for the c-isoform and translates to a protein with 919 amino acids. Compared to the c-isoform, the b-isoform lacks 6 amino acids inserted between exon 13 and 14. The a-isoform lacks an additional 37 amino acids in the juxtamembrane region as a result of alternative splicing of exon 10 to exon 12. DDR1b protein is the predominant isoform expressed during embryogenesis, whereas the a-isoform is upregulated in certain human mammary carcinoma cell lines. The relative expression ratio and the post-translational modification of the a- and b-isoform seem to underlie complex regulatory mechanisms. Overexpression of DDR1a and DDR1b in human embryonic kidney fibroblast 293 cells revealed a differential glycosylation pattern of the two isoforms. The alternatively spliced 37 amino acids insert in DDR1b contains the motif LLXNPXY, which can associate with the phosphotyrosine-binding domain of the Shc adaptor protein upon collagen-induced tyrosine phosphorylation. The fibroblast-growth factor receptor substrate 2 (FRS2) binds to a chimeric molecule containing the juxtamembrane region of DDR1a

Molecular Families

• Families in which DDR1 is a member
  • DDR1-->ddr -->PTK -->protein kinase -->kinases

Names

• DDR1 [HUGO gene name]
• tyrosine kinase receptor E (trkE , trk6 )
• cell adhesion kinase (cak )
• epithelial discoidin domain receptor precursor 1 (eddr1 )
• discoidin domain receptor family, member 1 (DDR1 )
• neuroepithelial tyrosine kinase (NEP , neurotrophic tyrosine kinase, receptor, type 4 ) [mouse ]
• protein tyrosine kinase 3A (PTK3A ) [rat ]
• CD167a
• mammarian carcinoma kinase 10 (MCK10 )
• receptor tyrosine kinase 6 (RTK6 )
• novel tyrosine kinase 4 (NTRK4 )

Major Links

• LocusLink: 780
• Mendelian Inheritance in Man (OMIM): 600408
• SwissProt annotated protein record: Q08345 [human], Q03146 [mouse], Q63474 [rat]

Author's Additional Insights

• The binding to collagen and the overexpression in various carcinomas suggest a role of DDR1 in tumor invasion and metastasis

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SYSTEM VIEW Disease Relevance / Function in Vivo

• To date, no human genetic disease is known that is linked to DDR1
• DDR1 knockout mice are smaller in size, particular females
• Blastocyst implantation is perturbed in the majority of knockout females
• Knockout females that reproduce fail to lactate due to malformation of the mammary gland

Cellular Function

• DDR1 is activated by fibrillar collagens (type I, II, III and V) as well as basement membrane collagen (IV and VIII)
• Upon stimulation with collagen, the tyrosine kinase is activated
• Activation follows slow kinetics, maximal activation is seen 2 - 18 h after stimulation
• In the alternatively spliced insert of DDR1b, the tyrosine in the sequence LLXNPXY becomes phosphorylated and binds to the PTB domain of the ShcA adaptor protein
• The juxtamembrane region of DDR1a binds to the adaptor FRS2
• No further downstream target has been identified

Protein Location

• Plasma membrane

Cellular Expression

• Mainly expressed in epithelial cells
• Human:
  • mammary gland
  • kidney
  • lung
  • colon
  • thyroid
  • brain
  • islets of Langerhans
• Tumors:
  • breast
  • ovarian
  • esophageal
  • pediatric brain
• Mouse development: early marker for neuroectodermal cells

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GENE Gene Sequence Links

• GenBank Accession Code: AB023050 , AC004211 , U48705 [complete cds]

Chromosomal Location

• 6p21.3 [human: The locus 6q16 has not be confirmed by others. Southern hybridization excludes the presence of a second DDR1 gene (W. Vogel)]
• 17C [mouse]

Gene Polymorphism

• No information

Transcription Regulating Molecules

Transcription_Factor	Comment
gamma-radiation	Expression of DDR1 in rat astrocytes can be induced by gamma-radiation
p53	The promoter of DDR1 contains a p53 consensus site. Transfection of p53 into human osteosarcoma cells induces DDR1 expression

Gene Annotation

• No information

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TRANSCRIPT Transcript Sequence Links

• GenBank Accession Code: NM_013994 [splice variant 3], NM_001954 [splice variant 2], NM_013993 [splice variant 1], X74979 , L20817 , Z29093 , L11315 , L57508 , NM_007584 [mouse], L57509 [mouse], AF026259 [mouse], AP000511 [chromosome 6p21.3, HLA Class I region, section], NM_013137 [rat], L26525 [rat]

Post-transcriptional Modification

• DDR1 shows alternative splicing in the juxtamembrane region and the kinase domain
• The longest transcript is DDR1c (NM_013994)
• Deletion of 18 bp in the kinase region results in the DDR1b isoform (NM_001954). A cryptic splice acceptor site has been identified 5' of exon 14
• Deletion of exon 11 (111bp) in the juxtamembrane region of DDR1b results in DDR1a (NM_013993). A possible mechanism for production of this splice variant may be the presence of an inverted repeat at the 3' end of the exon/intron boundary which allows the formation of a hairpin structure
• Message stability has not been studied

Transcript Annotation

• A single transcript of approximately 4.4 kb is detected by Northern hybridization

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PROTEIN Biochemical Activity

• DDR1 is a tyrosine kinase activated by collagen
• Compared to other tyrosine kinases, DDR1 activation follows slow kinetics

Protein Sequence Links

• SwissProt annotated protein record: Q08345 [human], Q03146 [mouse], Q63474 [rat]

Protein Sequence Annotation

• Discoidin domains (also called Factor VIII-homology or DS domains) are found in a variety of other proteins
• Transmembrane proteins with discoidin domain:
  • DDR2
  • Neurexin
  • Neuropilin (A5 antigen in Xenopus)
• Secreted proteins with discoidin domain:
  • Blood clotting factor V
  • Blood clotting factor VIII
  • AEBP1
  • MFG-E8
  • BA46
  • Del-1
  • XLRS-1
• Kinase domain has high homology to mammalian TrkA, B and C, and to the marine sponge tyrosine kinase receptor GCTK (from Geodia cydonium)

Protein Polymorphism

• No information

Protein Physical Properties

• DDR1a and DDR1b are differentially glycosylated
• Several tyrosines become phosphorylated upon receptor activation
• Tyrosine 513 of DDR1b (part of the motif LLXNPXY) has been mapped as phosphorylation site
• About 10% of DDR1 is proteolytically processed yielding a 52 kDa soluble protein (alpha-subunit) and a 62 kDa transmembrane protein (beta-subunit)
• The beta-subunit remains in the membrane, the alpha-subunit can be purified from the supernatant
• The Furin recognition site RFRR (amino acid 304-307) may be utilized for cleavage (shedding) of DDR1

Post-translational Modification

• No information

Protein Structure Links

• No information

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MOLECULAR INTERACTIONS Molecular Pathways

• Collagen-induced signaling
• Non-proliferative

Enzymes for which this is a Substrate

• No substrates for DDR1 have been identified

Substrates

• The protease involved in DDR1 shedding has not been identified

Other Ligands and Associated Molecules

Molecule	Comment
ShcA	ShcA binds to LLXNPXpY site of DDR1b
FRS2	FRS2 binds to DDR1a

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REAGENTS Model Animal Strains

• A null mutation for DDR1 has been created and is currently under investigation {Vogel_W/Pawson_T.,unpublished results}

Monoclonal Antibodies

mAb	Supplier	Comment
48B3	Hans-Jorg Buehring	mouse IgG3
51D6	Hans-Jorg Buehring	mouse IgM

• No commercially available monoclonal antibodies yet

Polyclonal Antibodies

Antibody	Supplier	Comment
DDR1 (C-20)	Santa Cruz ( sc-532 )	Works well in Western blotting, not in IP
DDR1 (N-13)	Santa Cruz ( sc-7553 )	Does not work in WB (communicated by F. Alves)
DDR1 (H-126)	Santa Cruz ( sc-8988 )	Does not work in our hands (WB, IP, IH tested)
345	W. Vogel	Polyclonal rabbit against extracellular domain; works well if protein is over-expressed

Drugs and Small Molecules

• No information

Genetic Constructs

Construct	Supplier	Comment
pRK5-DDR1a	Dr. Axel Ullrich MPI Martinried	See NOTE
pRK5-DDR1b	Dr. Axel Ullrich MPI Martinried	See NOTE

• NOTE: Used for transient expression in 293 cells

Purified Protein

Protein	Supplier	Comment
discoidin domain expressed with a His-tag in E.coli	{Vogel_W/Pawson_T.1997.MC}	Binds to collagen in vitro

Reagents Misc.

• No information

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REFERENCES References

REVIEWS
1. {Alves_F/Ullrich_A..Molekularbiologische_Grundlagen_der_Gastroenterologie}
Alves F, Vogel W, Ullrich A. . Tumorinvasion - die Rolle der Rezeptoren. In Beger HG, Manns M, Greten H. 1995. Molekularbiologische Grundlagen der Gastroenterologie. Springer-Verlag GmbH & Co. KG p
2. {Vogel_W.1999.FJ}
Vogel W. 1999. Discoidin domain receptors: structural relations and functional implications. FASEB J 13:S77-S82

PRIMARY CITATIONS
3. {Alves_F/Ullrich_A.1995.ONCOG}
Alves F, Vogel W, Mossie K, Millauer B, Hofler H, Ullrich A. 1995. Distinct structural characteristics of discoidin I subfamily receptor tyrosine kinases and complementary expression in human cancer. Oncogene 10:609-618
4. {Barker_KT/Crompton_MR.1995.ONCOG}
Barker KT, Martindale JE, Mitchell PJ, Kamalati T, Page MJ, Phippard DJ, Dale TC, Gusterson BA, Crompton MR. 1995. Expression patterns of the novel receptor-like tyrosine kinase, DDR, in human breast tumours. Oncogene 10:569-575
5. {Di_Marco_E/De_Luca_M.1993.JBC}
Di Marco E, Cutuli N, Guerra L, Cancedda R, De Luca M. 1993. Molecular cloning of trkE, a novel trk-related putative tyrosine kinase receptor isolated from normal human keratinocytes and widely expressed by normal human tissues. J Biol Chem 268:24290-24295
6. {Edelhoff_S/Disteche_CM.1995.GENOM}
Edelhoff S, Sweetser DA, Disteche CM. 1995. Mapping of the NEP receptor tyrosine kinase gene to human chromosome 6p21.3 and mouse chromosome 17C. Genomics 25:309-311
7. {Foehr_ED/Bradshaw_RA.2000.FJ}
Foehr ED, Tatavos A, Tanabe E, Raffioni S, Goetz S, Dimarco E, De Luca M, Bradshaw RA. 2000. Discoidin domain receptor 1 (DDR1) signaling in PC12 cells: activation of juxtamembrane domains in PDGFR/DDR/TrkA chimeric receptors. FASEB J 14:973-981
8. {Johnson_JD/Rutter_WJ.1993.PNASU}
Johnson JD, Edman JC, Rutter WJ. 1993. A receptor tyrosine kinase found in breast carcinoma cells has an extracellular discoidin I-like domain. Proc Natl Acad Sci U S A 90:5677-5681
9. {Laval_S/Ganesan_TS.1994.CGD}
Laval S, Butler R, Shelling AN, Hanby AM, Poulsom R, Ganesan TS. 1994. Isolation and characterization of an epithelial-specific receptor tyrosine kinase from an ovarian cancer cell line. Cell Growth Differ 5:1173-1183
10. {Nemoto_T/Hirokawa_K.1997.PATHO}
Nemoto T, Ohashi K, Akashi T, Johnson JD, Hirokawa K. 1997. Overexpression of protein tyrosine kinases in human esophageal cancer. Pathobiology 65:195-203
11. {No_Authors1999.NATUR}
Complete sequence and gene map of a human major histocompatibility complex. The MHC sequencing consortium.
12. {Perez_JL/Wong_TW.1994.ONCOG}
Perez JL, Shen X, Finkernagel S, Sciorra L, Jenkins NA, Gilbert DJ, Copeland NG, Wong TW. 1994. Identification and chromosomal mapping of a receptor tyrosine kinase with a putative phospholipid binding sequence in its ectodomain. Oncogene 9:211-219
13. {Perez_JL/Wong_TW.1996.ONCOG}
Perez JL, Jing SQ, Wong TW. 1996. Identification of two isoforms of the Cak receptor kinase that are coexpressed in breast tumor cell lines. Oncogene 12:1469-1477
14. {Playford_MP/Ganesan_TS.1996.GR}
Playford MP, Butler RJ, Wang XC, Katso RM, Cooke IE, Ganesan TS. 1996. The genomic structure of discoidin receptor tyrosine kinase. Genome Res 6:620-627
15. {Ruvkun_G/Hobert_O.1998.SCIEN}
Ruvkun G, Hobert O. 1998. The taxonomy of developmental control in Caenorhabditis elegans. Science 282:2033-2041
16. {Sakuma_S/Abe_H.1996.FL}
Sakuma S, Saya H, Tada M, Nakao M, Fujiwara T, Roth JA, Sawamura Y, Shinohe Y, Abe H. 1996. Receptor protein tyrosine kinase DDR is up-regulated by p53 protein. FEBS Lett 398:165-169
17. {Sanchez_MP/Barbacid_M.1994.PNASU}
Sanchez MP, Tapley P, Saini SS, He B, Pulido D, Barbacid M. 1994. Multiple tyrosine protein kinases in rat hippocampal neurons: isolation of Ptk-3, a receptor expressed in proliferative zones of the developing brain. Proc Natl Acad Sci U S A 91:1819-1823
18. {Shrivastava_A/Yancopoulos_GD.1997.MC}
Shrivastava A, Radziejewski C, Campbell E, Kovac L, McGlynn M, Ryan TE, Davis S, Goldfarb MP, Glass DJ, Lemke G, Yancopoulos GD. 1997. An orphan receptor tyrosine kinase family whose members serve as nonintegrin collagen receptors. Mol Cell 1:25-34
19. {Vogel_W/Pawson_T.1997.MC}
Vogel W, Gish GD, Alves F, Pawson T. 1997. The discoidin domain receptor tyrosine kinases are activated by collagen. Mol Cell 1:13-23
20. {Vogel_W/Pawson_T.2000.JBC}
Vogel W, Brakebusch C, Fassler R, Alves F, Ruggiero F, Pawson T. 2000. Discoidin domain receptor 1 is activated independently of beta(1) integrin. J Biol Chem 275:5779-5784
21. {Weiner_HL/Ziff_EB.1996.PN}
Weiner HL, Rothman M, Miller DC, Ziff EB. 1996. Pediatric brain tumors express multiple receptor tyrosine kinases including novel cell adhesion kinases. Pediatr Neurosurg 25:64-71
22. {Zerlin_M/Goldfarb_M.1993.ONCOG}
Zerlin M, Julius MA, Goldfarb M. 1993. NEP: a novel receptor-like tyrosine kinase expressed in proliferating neuroepithelia. Oncogene 8:2731-2739

WWW Resources
23. Human Genome Mapping Project: Gene DDR1

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* indicates amended by reviewer, ** indicates added by reviewer
Modified 09/22/00 mpr@mail.nih.gov