Subcellular localization of LIM proteins in chicken retina

BEJARANO, CLAUDIO; FOSSER, NICOLÁS; PAGANELLI, ALEJANDRA; RÍOS, HUGO

Buenos Aires

Simposio; II Simposio Franco-Argentino de Neurociencias; 2012

LIA DEVENIR

Subcellular localization of LIM domain proteins in chicken retinaBejarano, Claudio A.; Fosser, Nicolás S.; Paganelli, Alejandra R. and Ríos, Hugo.Instituto de Biol. Celular y Neurociencia, ?Prof. E. de Robertis?, Facultad de Medicina, UBA-CONICETProtein with LIM domains are involved in different neuronal functions. LIM proteins couldfunction as adapters and molecular biosensors acting as shuttle between nucleus and cytoplasm,controlling gene expression, cellular cytoarchitecture, adhesion and motility. Other well-knownfunctions are related to oncogenesis and pathogenesis of some neurological illness as Parkinson?sdisease and ADHD.It has been described 4 subfamilies according to the genetic structure and function. The ALPsubfamily, which has actin-binding domains and PDZ-LIM domains (e.g.: CLP36 (PDLIM1), ALP(PDLIM3) and RIL); the Enigma subfamily; the LIMK subfamily and the LMO7 subfamily whose are theclassical transcription factors (e.g. Lhx1/2 and ISL1). Subcellular localization of these proteins is crucialfor their function, since LIM proteins act regulating some kinases, phosphatases and transcriptionfactors according to the subcellular localization.There is little information about the role of ALP/CLP36 and ISL1/2 or Lhx in retina. The presentstudy described the localization of some LIM proteins in the chick retina, by immunohistochemistryand western blot, in the soma of horizontal and photoreceptors cells, as well as at the synaptic ending(synaptosomal fraction). Using an antibody which detects CLP3 and ALP (PDLIM 1-3) we observed thatthe synaptic endings of double cones are stained. In view of the fact of the structural similarity ofCLP36 and RIL we argue that CLP36 could be associated to functional modifications of the synapticterminals.On the other hand, classical transcriptions factors as ISL1 and Lhx1/2 are both localized at thenucleus and terminal endings of horizontal cells, suggesting a non-canonical function. Ourobservations rise new questions about the regulatory pathways of these proteins LIM and its potentialrole in synaptic plasticity and neuroplasticity during development and also in the context ofneurodegenerative disorders or metabolic diseases. PIP00404