Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Echinobase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Development 2015 Oct 15;14220:3537-48. doi: 10.1242/dev.126144.
Show Gene links Show Anatomy links

ABCC5 is required for cAMP-mediated hindgut invagination in sea urchin embryos.

Shipp LE , Hill RZ , Moy GW , Gökırmak T , Hamdoun A .

ATP-binding cassette (ABC) transporters are evolutionarily conserved proteins that pump diverse substrates across membranes. Many are known to efflux signaling molecules and are extensively expressed during development. However, the role of transporters in moving extracellular signals that regulate embryogenesis is largely unexplored. Here, we show that a mesodermal ABCC (MRP) transporter is necessary for endodermal gut morphogenesis in sea urchin embryos. This transporter, Sp-ABCC5a (C5a), is expressed in pigment cells and their precursors, which are a subset of the non-skeletogenic mesoderm (NSM) cells. C5a expression depends on Delta/Notch signaling from skeletogenic mesoderm and is downstream of Gcm in the aboral NSM gene regulatory network. Long-term imaging of development reveals that C5a knockdown embryos gastrulate, but ∼90% develop a prolapse of the hindgut by the late prism stage (∼8 h after C5a protein expression normally peaks). Since C5a orthologs efflux cyclic nucleotides, and cAMP-dependent protein kinase (Sp-CAPK/PKA) is expressed in pigment cells, we examined whether C5a could be involved in gastrulation through cAMP transport. Consistent with this hypothesis, membrane-permeable pCPT-cAMP rescues the prolapse phenotype in C5a knockdown embryos, and causes archenteron hyper-invagination in control embryos. In addition, the cAMP-producing enzyme soluble adenylyl cyclase (sAC) is expressed in pigment cells, and its inhibition impairs gastrulation. Together, our data support a model in which C5a transports sAC-derived cAMP from pigment cells to control late invagination of the hindgut. Little is known about the ancestral functions of ABCC5/MRP5 transporters, and this study reveals a novel role for these proteins in mesoderm-endoderm signaling during embryogenesis.

PubMed ID: 26395488
PMC ID: PMC4631766
Article link: Development
Grant support: [+]

Genes referenced: abcb6 abcc2 abcc3a adcy10 gcml LOC100887844 LOC115921237 LOC575116 LOC582918 LOC586799 LOC588563 LOC589947
Antibodies: abcc3a Ab1
Morpholinos: LOC105447431 MO2 abcc2 MO1 abcc2 MO2

References [+] :
Ammerman, Uptake of Cyclic AMP by Natural Populations of Marine Bacteria. 1982, Pubmed