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PIST regulates the intracellular trafficking and plasma membrane expression of cadherin 23.

Xu Z, Oshima K, Heller S - BMC Cell Biol. (2010)

Bottom Line: PIST, a Golgi-associated, PDZ domain-containing protein, interacted with cadherin 23 via the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI) of cadherin 23.PIST binds cadherin 23 via its PDZ domain and retains cadherin 23 in trans-Golgi network.MAGI-1 and harmonin can compete with PIST for binding cadherin 23 and release cadherin 23 from PIST's retention.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Otolaryngology--Head & Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA. xuzg@sdu.edu.cn

ABSTRACT

Background: The atypical cadherin protein cadherin 23 (CDH23) is crucial for proper function of retinal photoreceptors and inner ear hair cells. As we obtain more and more information about the specific roles of cadherin 23 in photoreceptors and hair cells, the regulatory mechanisms responsible for the transport of this protein to the plasma membrane are largely unknown.

Results: PIST, a Golgi-associated, PDZ domain-containing protein, interacted with cadherin 23 via the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI) of cadherin 23. By binding to cadherin 23, PIST retained cadherin 23 in the trans-Golgi network of cultured cells. The retention was released when either of the two known cadherin 23-binding proteins MAGI-1 and harmonin was co-expressed. Similar to MAGI-1 and harmonin, PIST was detected in mouse inner ear sensory hair cells.

Conclusions: PIST binds cadherin 23 via its PDZ domain and retains cadherin 23 in trans-Golgi network. MAGI-1 and harmonin can compete with PIST for binding cadherin 23 and release cadherin 23 from PIST's retention. Our finding suggests that PIST, MAGI-1 and harmonin collaborate in intracellular trafficking of cadherin 23 and regulate the plasma membrane expression of cadherin 23.

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Interaction between PIST and cadherin 23. A. Schematic diagram of chicken cadherin 23 domain structure and the intracellular fragment used as the bait for yeast two-hybrid screens. B. Schematic diagram of chicken PIST domain structure and PIST protein fragments encoded by the clones isolated from yeast two-hybrid screens. C. Western blots showing co-immunoprecipitation (co-IP) of EGFP-tagged human PIST protein with Myc-tagged mouse cadherin 23(+68) and cadherin 23(-68). The co-IP is almost undetectable when the last 4 amino acids (ITEL) of cadherin 23 are deleted. IP indicates antibody used for immunoprecipitation and WB indicates antibody used for detection.
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Figure 1: Interaction between PIST and cadherin 23. A. Schematic diagram of chicken cadherin 23 domain structure and the intracellular fragment used as the bait for yeast two-hybrid screens. B. Schematic diagram of chicken PIST domain structure and PIST protein fragments encoded by the clones isolated from yeast two-hybrid screens. C. Western blots showing co-immunoprecipitation (co-IP) of EGFP-tagged human PIST protein with Myc-tagged mouse cadherin 23(+68) and cadherin 23(-68). The co-IP is almost undetectable when the last 4 amino acids (ITEL) of cadherin 23 are deleted. IP indicates antibody used for immunoprecipitation and WB indicates antibody used for detection.

Mentions: To identify proteins that interact with cadherin 23, we performed yeast two-hybrid screens of a chicken basilar papilla cDNA library using the intracellular part of chicken cadherin 23(+68) protein as a bait (Figure 1A). Proteins identified through the yeast two-hybrid screen include scaffolding proteins (for example, MAGI-1 [4]) and chaperones (such as PIST, see below), most but not all of which are PDZ domain-containing proteins. Twenty-nine clones, which account for more than half of all the isolated positive clones, encode the chicken PDZ-containing, Golgi-associated chaperone protein PIST. The isolated 29 PIST clones fall into 10 groups of unique cDNAs, covering different lengths of PIST's amino acid sequence (Figure 1B). The longest clone encodes nearly the full-length chicken PIST, only missing the N-terminal 85 amino acids comparing to the predicted chicken PIST sequence in NCBI database, and the shortest contains the second coiled-coil domain and the PDZ domain.


PIST regulates the intracellular trafficking and plasma membrane expression of cadherin 23.

Xu Z, Oshima K, Heller S - BMC Cell Biol. (2010)

Interaction between PIST and cadherin 23. A. Schematic diagram of chicken cadherin 23 domain structure and the intracellular fragment used as the bait for yeast two-hybrid screens. B. Schematic diagram of chicken PIST domain structure and PIST protein fragments encoded by the clones isolated from yeast two-hybrid screens. C. Western blots showing co-immunoprecipitation (co-IP) of EGFP-tagged human PIST protein with Myc-tagged mouse cadherin 23(+68) and cadherin 23(-68). The co-IP is almost undetectable when the last 4 amino acids (ITEL) of cadherin 23 are deleted. IP indicates antibody used for immunoprecipitation and WB indicates antibody used for detection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2967513&req=5

Figure 1: Interaction between PIST and cadherin 23. A. Schematic diagram of chicken cadherin 23 domain structure and the intracellular fragment used as the bait for yeast two-hybrid screens. B. Schematic diagram of chicken PIST domain structure and PIST protein fragments encoded by the clones isolated from yeast two-hybrid screens. C. Western blots showing co-immunoprecipitation (co-IP) of EGFP-tagged human PIST protein with Myc-tagged mouse cadherin 23(+68) and cadherin 23(-68). The co-IP is almost undetectable when the last 4 amino acids (ITEL) of cadherin 23 are deleted. IP indicates antibody used for immunoprecipitation and WB indicates antibody used for detection.
Mentions: To identify proteins that interact with cadherin 23, we performed yeast two-hybrid screens of a chicken basilar papilla cDNA library using the intracellular part of chicken cadherin 23(+68) protein as a bait (Figure 1A). Proteins identified through the yeast two-hybrid screen include scaffolding proteins (for example, MAGI-1 [4]) and chaperones (such as PIST, see below), most but not all of which are PDZ domain-containing proteins. Twenty-nine clones, which account for more than half of all the isolated positive clones, encode the chicken PDZ-containing, Golgi-associated chaperone protein PIST. The isolated 29 PIST clones fall into 10 groups of unique cDNAs, covering different lengths of PIST's amino acid sequence (Figure 1B). The longest clone encodes nearly the full-length chicken PIST, only missing the N-terminal 85 amino acids comparing to the predicted chicken PIST sequence in NCBI database, and the shortest contains the second coiled-coil domain and the PDZ domain.

Bottom Line: PIST, a Golgi-associated, PDZ domain-containing protein, interacted with cadherin 23 via the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI) of cadherin 23.PIST binds cadherin 23 via its PDZ domain and retains cadherin 23 in trans-Golgi network.MAGI-1 and harmonin can compete with PIST for binding cadherin 23 and release cadherin 23 from PIST's retention.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Otolaryngology--Head & Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA. xuzg@sdu.edu.cn

ABSTRACT

Background: The atypical cadherin protein cadherin 23 (CDH23) is crucial for proper function of retinal photoreceptors and inner ear hair cells. As we obtain more and more information about the specific roles of cadherin 23 in photoreceptors and hair cells, the regulatory mechanisms responsible for the transport of this protein to the plasma membrane are largely unknown.

Results: PIST, a Golgi-associated, PDZ domain-containing protein, interacted with cadherin 23 via the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI) of cadherin 23. By binding to cadherin 23, PIST retained cadherin 23 in the trans-Golgi network of cultured cells. The retention was released when either of the two known cadherin 23-binding proteins MAGI-1 and harmonin was co-expressed. Similar to MAGI-1 and harmonin, PIST was detected in mouse inner ear sensory hair cells.

Conclusions: PIST binds cadherin 23 via its PDZ domain and retains cadherin 23 in trans-Golgi network. MAGI-1 and harmonin can compete with PIST for binding cadherin 23 and release cadherin 23 from PIST's retention. Our finding suggests that PIST, MAGI-1 and harmonin collaborate in intracellular trafficking of cadherin 23 and regulate the plasma membrane expression of cadherin 23.

Show MeSH
Related in: MedlinePlus