Characterization of a hemocyte intracellular fatty acid‐binding protein from crayfish (Pacifastacus leniusculus) and shrimp (Penaeus monodon)

Abstract

Intracellular fatty acid-binding proteins (FABPs) are small members of the superfamily of lipid-binding proteins, which occur in invertebrates and vertebrates. Included in this superfamily are the cellular retinoic acid-binding proteins and retinol-binding proteins, which seem to be restricted to vertebrates. Here, we report the cDNA cloning and characterization of two FABPs from hemocytes of the freshwater crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon. In both these proteins, the binding triad residues involved in interaction with ligand carboxylate groups are present. From the sequence and homology modeling, the proteins are probably FABPs and not retinoic acid-binding proteins. The crayfish transcript (plFABP) was detected at high level in hemocytes, hepatopancreas, intestine and ovary and at low level in hematopoietic tissue and testis. Its expression in hematopoietic cells varied depending on the state of the crayfish from which it was isolated. Expression was 10-15 times higher in cultures isolated from crayfish with red colored plasma, in which hemocyte synthesis was high, if retinoic acid was added to the culture medium. In normal colored crayfish, with normal levels of hemocytes, no increase in expression of p1FABP was detected. Two other putative plFABP ligands, stearic acid and oleic acid, did not have any effect on plFABP expression in hematopoietic cells. These results suggest that retinoic acid-dependent signaling may be present in crustaceans.

Evolution of Retinoid and Steroid Signaling: Vertebrate Diversification from an Amphioxus Perspective

“…Human RDH5 and RDH16 are involved in visual and general retinol oxidation, respectively (Gough et al 1998; Yamamoto et al 1999), although both of them also show some activity toward steroids. In addition, HSD17β6 and DHRS9 are also active against both retinoids and steroids (Biswas and Russell 1997; Chetyrkin, Belyaeva, et al 2001; Chetyrkin, Hu, et al 2001; Soref et al 2001), whereas SDR9C7 does not have a significant activity against steroids and shows only very weak retinaldehyde reductase activity (Kowalik et al 2009). A total of 12 amphioxus sequences, named Bf_Rdh_1 to 12, group with the vertebrate Rdh cluster (fig.…”

Retinoic acid signaling in development: Tissue‐specific functions and evolutionary origins

“…Although there are now some data on devel- opmental roles of RA signaling emerging from invertebrate chordates, there is still an obvious lack of information on the role(s) of RA in non-chordates. Even if low concentrations of 9-cis and all-trans RA have been observed in regenerating limb blastemas of the crab Uca pugilator (Hopkins, 2001) and effects of treatments with RA agonists or antagonists have been described in sea urchins (Sciarrino and Matranga, 1995;Kuno et al, 1999), mollusks (Créton et al, 1993) crustaceans (Chung et al, 1998;Hopkins, 2001;Söderhäll et al, 2006), insects (Picking et al, 1996;Shim et al, 1997;Sun et al, 1993), planarians (Romero and Bueno, 2001), cnidarians (Müller, 1984), and sponges (Imsiecke et al, 1994;Nikko et al, 2001;Wiens et al, 2003), the actual presence and putative roles of RA signaling during development in these taxa remain elusive. Thus, to fully understand the origin and evolution of RA signaling during embryonic development, we need to broaden the sampling of animal taxa and apply more sophisticated experimental tools to non-vertebrate model systems.…”

Differential gene expression in diapausing and active Calanus finmarchicus (Copepoda)

“…FABP is related to cytosolic fatty acid binding proteins and retinoid binding proteins. FABPs are involved in cellular transport, utilization, and storage of fatty acids (Söderhäll et al 2006). FABP family members also bind and transport retinoids with high affinity and help to regulate the amount of ligand available to retinoid receptors (Zimmerman & Veerkamp 2002).…”