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Goodman KM, Katsamba PS, Rubinstein R, Ahlsén G, Bahna F, Mannepalli S, Dan H, Sampogna RV, Shapiro L, Honig B. How clustered protocadherin binding specificity is tuned for neuronal self-/nonself-recognition. eLife 2022; 11:e72416. [PMID: 35253643 PMCID: PMC8901172 DOI: 10.7554/elife.72416] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/26/2022] [Indexed: 12/30/2022] Open
Abstract
The stochastic expression of fewer than 60 clustered protocadherin (cPcdh) isoforms provides diverse identities to individual vertebrate neurons and a molecular basis for self-/nonself-discrimination. cPcdhs form chains mediated by alternating cis and trans interactions between apposed membranes, which has been suggested to signal self-recognition. Such a mechanism requires that cPcdh cis dimers form promiscuously to generate diverse recognition units, and that trans interactions have precise specificity so that isoform mismatches terminate chain growth. However, the extent to which cPcdh interactions fulfill these requirements has not been definitively demonstrated. Here, we report biophysical experiments showing that cPcdh cis interactions are promiscuous, but with preferences favoring formation of heterologous cis dimers. Trans homophilic interactions are remarkably precise, with no evidence for heterophilic interactions between different isoforms. A new C-type cPcdh crystal structure and mutagenesis data help to explain these observations. Overall, the interaction characteristics we report for cPcdhs help explain their function in neuronal self-/nonself-discrimination.
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Affiliation(s)
- Kerry Marie Goodman
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Phinikoula S Katsamba
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Rotem Rubinstein
- School of Neurobiology, Biochemistry and Biophysics, Tel Aviv UniversityTel AvivIsrael
- Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - Göran Ahlsén
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Fabiana Bahna
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Seetha Mannepalli
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
| | - Hanbin Dan
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
| | - Rosemary V Sampogna
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
| | - Lawrence Shapiro
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
- Department of Biochemistry and Molecular Biophysics, Columbia UniversityNew YorkUnited States
| | - Barry Honig
- Zuckerman Mind, Brain and Behavior Institute, Columbia UniversityNew YorkUnited States
- Department of Medicine, Division of Nephrology, Columbia UniversityNew YorkUnited States
- Department of Biochemistry and Molecular Biophysics, Columbia UniversityNew YorkUnited States
- Department of Systems Biology, Columbia UniversityNew YorkUnited States
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Goodman KM, Rubinstein R, Dan H, Bahna F, Mannepalli S, Ahlsén G, Aye Thu C, Sampogna RV, Maniatis T, Honig B, Shapiro L. Protocadherin cis-dimer architecture and recognition unit diversity. Proc Natl Acad Sci U S A 2017; 114:E9829-37. [PMID: 29087338 DOI: 10.1073/pnas.1713449114] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Clustered protocadherins (Pcdhs) mediate numerous neural patterning functions, including neuronal self-recognition and non-self-discrimination to direct self-avoidance among vertebrate neurons. Individual neurons stochastically express a subset of Pcdh isoforms, which assemble to form a stochastic repertoire of cis-dimers. We describe the structure of a PcdhγB7 cis-homodimer, which includes the membrane-proximal extracellular cadherin domains EC5 and EC6. The structure is asymmetric with one molecule contributing interface surface from both EC5 and EC6, and the other only from EC6. Structural and sequence analyses suggest that all Pcdh isoforms will dimerize through this interface. Site-directed mutants at this interface interfere with both Pcdh cis-dimerization and cell surface transport. The structure explains the known restrictions of cis-interactions of some Pcdh isoforms, including α-Pcdhs, which cannot form homodimers. The asymmetry of the interface approximately doubles the size of the recognition repertoire, and restrictions on cis-interactions among Pcdh isoforms define the limits of the Pcdh recognition unit repertoire.
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Goodman KM, Rubinstein R, Thu CA, Mannepalli S, Bahna F, Ahlsén G, Rittenhouse C, Maniatis T, Honig B, Shapiro L. γ-Protocadherin structural diversity and functional implications. eLife 2016; 5. [PMID: 27782885 PMCID: PMC5106212 DOI: 10.7554/elife.20930] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/06/2016] [Indexed: 12/26/2022] Open
Abstract
Stochastic cell-surface expression of α-, β-, and γ-clustered protocadherins (Pcdhs) provides vertebrate neurons with single-cell identities that underlie neuronal self-recognition. Here we report crystal structures of ectodomain fragments comprising cell-cell recognition regions of mouse γ-Pcdhs γA1, γA8, γB2, and γB7 revealing trans-homodimers, and of C-terminal ectodomain fragments from γ-Pcdhs γA4 and γB2, which depict cis-interacting regions in monomeric form. Together these structures span the entire γ-Pcdh ectodomain. The trans-dimer structures reveal determinants of γ-Pcdh isoform-specific homophilic recognition. We identified and structurally mapped cis-dimerization mutations to the C-terminal ectodomain structures. Biophysical studies showed that Pcdh ectodomains from γB-subfamily isoforms formed cis dimers, whereas γA isoforms did not, but both γA and γB isoforms could interact in cis with α-Pcdhs. Together, these data show how interaction specificity is distributed over all domains of the γ-Pcdh trans interface, and suggest that subfamily- or isoform-specific cis-interactions may play a role in the Pcdh-mediated neuronal self-recognition code.
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Affiliation(s)
- Kerry Marie Goodman
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Rotem Rubinstein
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Department of Systems Biology, Columbia University, New York, United States
| | - Chan Aye Thu
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Seetha Mannepalli
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Fabiana Bahna
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Howard Hughes Medical Institute, Columbia University, New York, United States
| | - Göran Ahlsén
- Department of Systems Biology, Columbia University, New York, United States.,Howard Hughes Medical Institute, Columbia University, New York, United States
| | - Chelsea Rittenhouse
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Tom Maniatis
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, United States
| | - Barry Honig
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Department of Systems Biology, Columbia University, New York, United States.,Howard Hughes Medical Institute, Columbia University, New York, United States.,Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, United States.,Department of Medicine, Columbia University, New York, United States
| | - Lawrence Shapiro
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States.,Department of Systems Biology, Columbia University, New York, United States.,Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, United States
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