Changes in reflectin protein phosphorylation are associated with dynamic iridescence in squid.
Many cephalopods exhibit remarkable dermal iridescence, a component of their complex, dynamic camouflage and communication. In the species Euprymna scolopes, the light-organ iridescence is static and is due to reflectin protein-based platelets assembled into lamellar thin-film reflectors called iridosomes, contained within iridescent cells called iridocytes. Squid in the family Loliginidae appear to be unique in which the dermis possesses a dynamic iridescent component with reflective, coloured structures that are assembled and disassembled under the control of the muscarinic cholinergic system and the associated neurotransmitter acetylcholine (ACh). Here we present the sequences and characterization of three new members of the reflectin family associated with the dynamically changeable iridescence in Loligo and not found in static Euprymna iridophores. In addition, we show that application of genistein, a protein tyrosine kinase inhibitor, suppresses ACh- and calcium-induced iridescence in Loligo. We further demonstrate that two of these novel reflectins are extensively phosphorylated in concert with the activation of iridescence by exogenous ACh. This phosphorylation and the correlated iridescence can be blocked with genistein. Our results suggest that tyrosine phosphorylation of reflectin proteins is involved in the regulation of dynamic iridescence in Loligo.
Izumi
Michi
M
Institute for Collaborative Biotechnologies, Materials Research Laboratory, California Nano-Systems Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Sweeney
Alison M
AM
Demartini
Daniel
D
Weaver
James C
JC
Powers
Meghan L
ML
Tao
Andrea
A
Silvas
Tania V
TV
Kramer
Ryan M
RM
Crookes-Goodson
Wendy J
WJ
Mäthger
Lydia M
LM
Naik
Rajesh R
RR
Hanlon
Roger T
RT
Morse
Daniel E
DE
D000109:Acetylcholine / Q000378:metabolism / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D003116:Color; D019833:Genistein / Q000494:pharmacology; D049834:Loligo / Q000033:anatomy & histology / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation / Q000187:drug effects; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction; D012867:Skin / Q000033:anatomy & histology / Q000378:metabolism
D011506:Proteins; D019833:Genistein; D000109:Acetylcholine