title: MULTIFUNCin: A Multifunctional Protein Cue Induces Habitat Selection by, and Predation on, Barnacles.
abstract: Foundation species provide critical resources to ecological community members and are major determinants of biodiversity. The barnacle Balanus glandula is one such species and dominates space among the higher reaches on wave-swept shores. Here, we show that B. glandula produces a 199.6-kDa glycoprotein (named "MULTIFUNCin"), and following secretion, a 390-kDa homodimer in its native state. MULTIFUNCin expression is localized in the epidermis, cuticle, and new shell material. Consequently, this molecule can specify upon contact the immediate presence of a live barnacle. Shared, conserved domains place MULTIFUNCin in the α2-macroglobulin (A2M) subgroup of the thioester-containing protein family. Although previously undescribed, MULTIFUNCin shares 78% nucleotide sequence homology with a settlement-inducing pheromone (SIP) of the barnacle, Amphibalanus amphitrite Based on this and further evidence, we propose that the two proteins are orthologues and evolved ancestrally in structural and immunological roles. More recently, they became exploited as chemical cues for con- and heterospecific organisms, alike. MULTIFUNCin and SIP both induce habitat selection (settlement) by conspecific barnacle larvae. In addition, MULTIFUNCin acts as a potent feeding stimulant to major barnacle predators (sea stars and several whelk species). Promoting immigration via settlement on the one hand, and death via predation on the other, MULTIFUNCin simultaneously mediates opposing demographic processes toward structuring both predator and prey populations. As a multifunctional protein cue, MULTIFUNCin provides valuable sensory information, conveys different messages to different species, and drives complex biotic interactions.
authors.affiliation: *Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA.
authors.forename: Graham A
authors.initials: GA
authors.lastname: Ferrier
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Kaddis
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.|UCLA/DOE Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Loo
authors.affiliation: *Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA.|Moreton Bay Research Station, Centre for Marine Science, and School of Biological Sciences, University of Queensland, St Lucia, Brisbane 4072, Queensland, Australia.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Ann Zimmer
authors.affiliation: *Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA z@biology.ucla.edu.|Moreton Bay Research Station, Centre for Marine Science, and School of Biological Sciences, University of Queensland, St Lucia, Brisbane 4072, Queensland, Australia.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Zimmer
mesh_terms: D000819:Animal Communication; D000818:Animals; D003463:Cues; D017753:Ecosystem; D015870:Gene Expression; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D007814:Larva; D011235:Predatory Behavior; D001468:Thoracica / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D006023:Glycoproteins