A uniform human Wnt expression library reveals a shared secretory pathway and unique signaling activities.
Wnt ligands are secreted morphogens that control multiple developmental processes during embryogenesis and adult homeostasis. A diverse set of receptors and signals have been linked to individual Wnts, but the lack of tools for comparative analysis has limited the ability to determine which of these signals are general for the entire Wnt family, and which define subsets of differently acting ligands. We have created a versatile Gateway library of clones for all 19 human Wnts. An analysis comparing epitope-tagged and untagged versions of each ligand shows that despite their similar expression at the mRNA level, Wnts exhibit considerable variation in stability, processing and secretion. At least 14 out of the 19 Wnts activate β-catenin-dependent signaling, an activity that is cell type-dependent and tracks with the stabilization of β-catenin and LRP6 phosphorylation. We find that the core Wnt modification and secretion proteins Porcupine (PORCN) and Wntless (WLS) are essential for all Wnts to signal through β-catenin-dependent and independent pathways. This comprehensive toolkit provides critical tools and new insights into human Wnt gene expression and function.
Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, USA.
Rani
R
Najdi
Kyle
K
Proffitt
Stephanie
S
Sprowl
Simran
S
Kaur
Jia
J
Yu
Tracy M
TM
Covey
David M
DM
Virshup
Marian L
ML
Waterman
D016475:3T3 Cells; D000217:Acyltransferases; D000818:Animals; D020869:Gene Expression Profiling; D015723:Gene Library; D057809:HEK293 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D060488:Low Density Lipoprotein Receptor-Related Protein-6 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D055571:Secretory Pathway; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000378:metabolism*
D047908:Intracellular Signaling Peptides and Proteins; C555475:LRP6 protein, human; D060488:Low Density Lipoprotein Receptor-Related Protein-6; D008565:Membrane Proteins; D043562:Receptors, G-Protein-Coupled; C549111:WLS protein, human; D051153:Wnt Proteins; D051176:beta Catenin; D000217:Acyltransferases; C491188:PORCN protein, human