p35 promotes the differentiation of amacrine cell subtype in the zebrafish retina under the regulation of egr1

Abstract

Background: Early growth response 1 (egr1) is a transcription factor (TF) for controlling the differentiation of Parvalbumin (Parv) -expressing amacrine cells (ACs) in zebrafish. However, the downstream factors of this process have not been identified. The purpose of this study was to investigate the role of p35, a neuronal-specific activator of cyclin-dependent kinase 5 (Cdk5) and a known in vitro target of egr1, in the differentiation of these ACs. Results: In the p35-knockdown retinas, Parv1 but not islet11 ACs were specifically reduced. This phenotype was highly similar to that in the Egr1-knockdown retinas. Furthermore, p35 expression was reduced in the Egr1-knockdown retinas, particularly in the AC region; while egr1 was only modestly reduced in this region in the p35-knockdown retinas. Conclusions: p35 likely acts downstream of egr1 to control the differentiation of Parv1 ACs. Developmental Dynamics 243:315-323, 2014. V C 2013 Wiley Periodicals, Inc.Key words: p35; cdk5r1b; zebrafish; retinal development; cdk5; egr1; amacrine cells; smarca4 Key findings:p35 knockdown compromised the differentiation of Parv1 but not Islet11 amacrine cells The observations were highly similar to that in the Egr1-knockdown retinas Gene perturbation analysis showed that p35 expression in the amacrine cell region was under the regulation of egr1.

Sigma-1 receptor regulates Tau phosphorylation and axon extension by shaping p35 turnover via myristic acid

“…Cdk5 activity is largely dependent on the availability of its activators, p35 and p39 (8,(15)(16)(17). Transcription of p35 is under the control of early growth response protein 1 (EGR-1) (18)(19)(20). p35 is degraded by two main pathways: the ubiquitin-proteasome pathway is the predominant form of degradation in fetal neurons, whereas, in adult neurons, p35 is preferentially cleaved to p25 by the calciumdependent protease calpain (21-23).…”