The CRIPTO/FRL-1/CRYPTIC (CFC) domain of human Cripto. Functional and structural insights through disulfide structure analysis.
The disulfide structure of the CRIPTO/FRL-1/CRYPTIC (CFC) domain of human Cripto protein was determined by a combination of enzymatic and chemical fragmentation, followed by chromatographic separation of the fragments, and characterization by mass spectrometry and N-terminal sequencing. These studies showed that Cys115 forms a disulfide bond with Cys133, Cys128 with Cys149, and Cys131 with Cys140. Protein database searching and molecular modeling revealed that the pattern of disulfide linkages in the CFC domain of Cripto is the same as that in PARS intercerebralis major Peptide C (PMP-C), a serine protease inhibitor, and that the EGF-CFC domains of Cripto are predicted to be structurally homologous to the EGF-VWFC domains of the C-terminal extracellular portions of Jagged 1 and Jagged 2. Biochemical studies of the interactions of ALK4 with the CFC domain of Cripto by fluorescence-activated cell sorter analysis indicate that the CFC domain binds to ALK4 independent of the EGF domain. A molecular model of the CFC domain of Cripto was constructed based on the nuclear magnetic resonance structure of PMP-C. This model reveals a hydrophobic patch in the domain opposite to the presumed ALK4 binding site. This hydrophobic patch may be functionally important for the formation of intra or intermolecular complexes.
Foley
Susan F
SF
Biogen, Inc., Cambridge Center, Cambridge, MA 02142, USA.
van Vlijmen
Herman W T
HW
Boynton
Raymond E
RE
Adkins
Heather B
HB
Cheung
Anne E
AE
Singh
Juswinder
J
Sanicola
Michele
M
Young
Carmen N
CN
Wen
Dingyi
D
D030201:Activin Receptors, Type I / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics; D006224:Cricetinae; D047169:Cyclotides; D004220:Disulfides / Q000737:chemistry; D004815:Epidermal Growth Factor; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D006801:Humans; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D000072101:Jagged-2 Protein; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011506:Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002352:Carrier Proteins; D047169:Cyclotides; D004220:Disulfides; D058851:GPI-Linked Proteins; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; C490504:JAG2 protein, human; D000072101:Jagged-2 Protein; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D011506:Proteins; D011994:Recombinant Proteins; C070636:TDGF1 protein, human; C072987:PMP-C peptide, insect; D004815:Epidermal Growth Factor; C425423:ACVR1 protein, human; C498932:ACVR1B protein, human; D030201:Activin Receptors, Type I