Subcellular Localization and Membrane Topology of the Melon Ethylene Receptor CmERS1

Abstract

Ethylene receptors are multispanning membrane proteins that negatively regulate ethylene responses via the formation of a signaling complex with downstream elements. To better understand their biochemical functions, we investigated the membrane topology and subcellular localization of CmERS1, a melon (Cucumis melo) ethylene receptor that has three putative transmembrane domains at the N terminus. Analyses using membrane fractionation and green fluorescent protein imaging approaches indicate that CmERS1 is predominantly associated with the endoplasmic reticulum (ER) membrane. Detergent treatments of melon microsomes showed that the receptor protein is integrally bound to the ER membrane. A protease protection assay and N-glycosylation analysis were used to determine membrane topology. The results indicate that CmERS1 spans the membrane three times, with its N terminus facing the luminal space and the large C-terminal portion lying on the cytosolic side of the ER membrane. This orientation provides a platform for interaction with the cytosolic signaling elements. The three N-terminal transmembrane segments were found to function as topogenic sequences to determine the final topology. High conservation of these topogenic sequences in all ethylene receptor homologs identified thus far suggests that these proteins may share the same membrane topology.

The Copper Transporter RAN1 Is Essential for Biogenesis of Ethylene Receptors in Arabidopsis

“…However, the subcellular localization of ETR1 and RAN1 when expressed in yeast remains to be determined. In Arabidopsis, ETR1 is an integral membrane protein located primarily in the membranes of the endoplasmic reticulum (45)(46)(47)(48)(49)(50)(51)(52). Although the subcellular location of RAN1 in Arabidopsis is unknown, our results suggest that it is co-localized in the same subcellular compartment with the receptors at some point during the biogenesis of the receptors in plants.…”

Aplicação de 1-metilciclopropeno e absorção de etileno em maçã da cultivar 'Royal Gala' colhida tardiamente

“…Este se liga aos receptores presentes na membrana do retículo endoplasmático Ciência Rural, v.40, n.10, out, 2010. (MA et al, 2006), transmitindo um sinal fisiológico para a síntese de enzimas que atuarão nos processos bioquímicos característicos do amadurecimento, como degradação da parede celular e quebra da clorofila (TAIZ & ZEIGER, 2004). A aplicação pós-colheita de 1-meticiclopropeno (1-MCP), inibidor da ação do etileno, pode manter a qualidade de frutos, como maçãs (BRACKMANN et al, 2004;CORRENT et al, 2004;, peras (LELIÈVRE et al, 1997), bananas (SISLER & SEREK, 1997) e abacates (KLUGE et al, 2002).…”

Aminoethoxyvinylglycine: isolated and combined with other growth regulators on quality of ‘Brookfield’ apples after storage

“…The lower ethylene production level of these treatments is related to the two ways in which ethylene management is employed in these treatments. In other words, the enzyme responsible for ethylene precursor production was inhibited by AVG (Yu and Yang, 1979;Ju and Curry, 2000) and the ethylene action by 1-MCP (Blankenship and Dole, 2003;Ma et al, 2006;Watkins, 2006) and by ethylene absorption (Brackmann et al, 2010;Corrêa et al, 2011).…”

“…1-MCP application blinds the ethylene receptors, thereby inhibiting the ethylene action and consequently fruit ripening (Blankenship and Dole, 2003;Ma et al, 2006). Ethylene absorption is also carried out in apple storage occasionally.…”