Invertebrate intracellular fatty acid binding proteins.

Esteves A, Ehrlich R.

Seccion Bioquimica, Dpto. de Biologia Celular y Molecular, Facultad de Ciencias

Montevideo, Uruguay.


Fatty acid binding proteins are multigenic cytosolic proteins largely

distributed along the zoological scale. Their overall identity at primary and

tertiary structure is conserved. They are involved in the uptake and transport

of hydrophobic ligands to different cellular fates. The precise functions of

each FABP type remain imperfectly understood, since sub-specialization of

functions is suggested. Evolutionary studies have distinguished major

subfamilies that could have been derived from a common ancestor close to

vertebrate/invertebrate split. Since the isolation of the first invertebrate

FABP from Schistocerca gregaria in 1990, the number of FABPs isolated from

invertebrates has been increasing. Differences at the sequence level are

appreciable and relationships with vertebrate FABPs are not clear, and lesser

among invertebrate proteins, introducing some uncertainty to infer functional

relatedness and phylogenetic relationships. The objective of this review is to

summarize the information available on invertebrate FABPs to elucidate their

mutual relationships, the relationship with their vertebrate counterparts and

putative functions. Structure, gene structure, putative functions, expression

studies and phylogenetic relationships with vertebrate counterparts are

analyzed. Previous suggestions of the ancestral position concerning the

heart-type of FABPs are reinforced by evidence from invertebrate models.