The periciliary ring in polarized epithelial cells is a hot spot for delivery of the apical protein gp135

Stoops, Emily H.; Hull, Michael; Olesen, Christina W.; Mistry, Kavita; Harder, Jennifer L.; Rivera‐Molina, Felix; Toomre, Derek; Caplan, Michael J.

doi:10.1085/jgp.1466oia69

Cited by 4 publications

(15 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In polarized epithelial cells, for example, multiple distinct vesicular carriers transport basolateral proteins to the basolateral plasma membrane and apical proteins to the apical surface. Each of these pathways manifests individual characteristics relating to their kinetic properties, inhibitor sensitivities and sites of delivery . This multiplicity of pathways available is thus in concert with our observations that pools of PC1 can pursue divergent itineraries with different biochemical properties.…”

Section: Discussionsupporting

confidence: 67%

Newly synthesized polycystin‐1 takes different trafficking pathways to the apical and ciliary membranes

Gilder

Chapin

Padovano

et al. 2018

Traffic

Self Cite

View full text Add to dashboard Cite

Mutations in the genes encoding polycystin-1 (PC1) and polycystin 2 (PC2) cause autosomal dominant polycystic kidney disease. These transmembrane proteins colocalize in the primary cilia of renal epithelial cells, where they may participate in sensory processes. PC1 is also found in the apical membrane when expressed in cultured epithelial cells. PC1 undergoes autocatalytic cleavage, producing an extracellular N-terminal fragment that remains noncovalently attached to the transmembrane C-terminus. Exposing cells to alkaline solutions elutes the N-terminal fragment while the C-terminal fragment is retained in the cell membrane. Utilizing this observation, we developed a "strip-recovery" synchronization protocol to study PC1 trafficking in polarized LLC-PK1 renal epithelial cells. Following alkaline strip, a new cohort of PC1 repopulates the cilia within 30 minutes, while apical delivery of PC1 was not detectable until 3 hours. Brefeldin A (BFA) blocked apical PC1 delivery, while ciliary delivery of PC1 was BFA insensitive. Incubating cells at 20°C to block trafficking out of the trans-Golgi network also inhibits apical but not ciliary delivery. These results suggest that newly synthesized PC1 takes distinct pathways to the ciliary and apical membranes. Ciliary PC1 appears to by-pass BFA sensitive Golgi compartments, while apical delivery of PC1 traverses these compartments.

show abstract

Section: Discussionsupporting

confidence: 67%

Newly synthesized polycystin‐1 takes different trafficking pathways to the apical and ciliary membranes

Gilder

Chapin

Padovano

et al. 2018

Traffic

Self Cite

View full text Add to dashboard Cite

show abstract

“…These data suggest that newly synthesized and recycling SNAP‐gp135 pursue distinct, non‐overlapping pathways to the apical membrane. This finding is consistent with our previous results demonstrating that these pools are delivered to separate regions of the apical membrane …”

Section: Resultssupporting

confidence: 94%

“…Our data suggest an interesting mechanistic model that accounts for the previously described delivery of newly synthesized gp135 to the periciliary region of the apical membrane (Figure ; Stoops et al). While the AEEs are distributed throughout the subapical region (Figures and A), the ARE is typically located centrally (Figure A,B), usually just below the primary cilium.…”

Section: Resultssupporting

confidence: 70%

“…Our results demonstrating the existence of different pathways for newly synthesized and recycling gp135 present an attractive model to accommodate our previous data showing that newly synthesized and recycling gp135 are delivered to different regions of the apical membrane (Figure 7; Stoops et al). Delivery of newly synthesized SNAP‐gp135 was concentrated in rings surrounding the ciliary exclusion zone.…”

Section: Discussionsupporting

confidence: 69%

“…Here, we use the SNAP tag system to follow the trafficking of newly synthesized gp135 from the trans‐Golgi network (TGN) to the apical membrane, looking specifically at the subcellular compartments gp135 traverses along the way. We have previously demonstrated that newly synthesized SNAP‐tagged gp135 is delivered to the cell surface in a restricted zone associated with the periciliary region of the apical membrane . Furthermore, our data suggest that a subset of gp135 traverses the basolateral membrane prior to apical delivery .…”

Section: Introductionmentioning

confidence: 56%

See 2 more Smart Citations

Newly synthesized and recycling pools of the apical protein gp135 do not occupy the same compartments

Stoops

Hull

Caplan

2016

Traffic

Self Cite

View full text Add to dashboard Cite

Polarized epithelial cells sort newly synthesized and recycling plasma membrane proteins into distinct trafficking pathways directed to either the apical or basolateral membrane domains. While the trans Golgi network is a well-established site of protein sorting, increasing evidence indicates a key role for endosomes in the initial trafficking of newly synthesized proteins. Both basolateral and apical proteins have been shown to traverse endosomes en route to the plasma membrane. In particular, apical proteins traffic through either subapical early or recycling endosomes. Here we use the SNAP tag system to analyze the trafficking of the apical protein gp135, also known as podocalyxin. We show that newly synthesized gp135 traverses the apical recycling endosome, but not the apical early endosomes. In contrast, post-endocytic gp135 is delivered to the apical early endosome before recycling back to the apical membrane. The pathways pursued by the newly synthesized and recycling gp135 populations do not detectably intersect, demonstrating that the biosynthetic and post-endocytic pools of this protein are subjected to distinct sorting processes.

show abstract

Mechanisms of ciliary targeting: entering importins and Rabs

Lü

Madugula

2017

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

Primary cilium is a rod-like plasma membrane protrusion that plays important roles in sensing the cellular environment and initiating corresponding signaling pathways. The sensory functions of the cilium critically depend on the unique enrichment of ciliary residents, which is maintained by the ciliary diffusion barrier. It is still unclear how ciliary cargoes specifically enter the diffusion barrier and accumulate within the cilium. In this review, the organization and trafficking mechanism of the cilium are compared to those of the nucleus, which are much better understood at the moment. Though the cilium differs significantly from the nucleus in terms of molecular and cellular functions, analogous themes and principles in the membrane organization and cargo trafficking are notable between them. Therefore, knowledge in the nuclear trafficking can likely shed light on our understanding of the ciliary trafficking. Here, with a focus on membrane cargoes in mammalian cells, we briefly review various ciliary trafficking pathways from the Golgi to the periciliary membrane. Models for the subsequent import translocation across the diffusion barrier and the enrichment of cargoes within the ciliary membrane are discussed in detail. Based on recent discoveries, we propose a Rab-importin-based model in an attempt to accommodate various observations on ciliary targeting.

show abstract

The periciliary ring in polarized epithelial cells is a hot spot for delivery of the apical protein gp135

Cited by 4 publications

References 28 publications

Newly synthesized polycystin‐1 takes different trafficking pathways to the apical and ciliary membranes

Newly synthesized polycystin‐1 takes different trafficking pathways to the apical and ciliary membranes

Newly synthesized and recycling pools of the apical protein gp135 do not occupy the same compartments

Mechanisms of ciliary targeting: entering importins and Rabs

Contact Info

Product

Resources

About