Exhibits chaperone activity toward chloroplast outer envelope membrane, mitochondrion outer membrane, endoplasmic reticulum membrane and peroxisomal proteins, by recruiting specific proteins containing a single transmembrane associated with an AKR2A-binding sequence (ABS) and subsequently binding glycolipids (e.g. monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG)) present in the membrane of the target organelle (PubMed:18193034, PubMed:20215589, PubMed:25203210). Seems to be involved in the regulation of hydrogen peroxide levels during biotic and abiotic stresses by optimizing the ascorbate peroxidase 3 (APX3) hydrogen peroxide-degrading activity. This regulation might be monitored by GRF6. Cytosolic targeting factor for chloroplast outer membrane (COM) proteins that mediates sorting and targeting of nascent chloroplast outer envelope membrane (OEM) proteins to the chloroplast. Facilitates the targeting of OEP7 to chloroplasts (PubMed:18193034). Facilitates the targeting of APX3 to peroxisomes. Involved in cellular metabolism (e.g. peroxisome activity) and required for plant growth and development (PubMed:20215589). Interacts with TOM20-4, CYTB5-E, CBR1, APX3, APX5, TOC34 and GRF6. Binds to chloroplast outer envelope membrane (OEM) protein targeting signals, as well as to chloroplasts. Interacts with OEP7 (PubMed:18193034). Binds to HSP17.8 via its ankyrin repeats, this interaction enhances chaperone activity and chloroplast binding. Interacts also with HSP17.4A, HSP17.6A and HSP18.1 (PubMed:21730198). Binds specifically to two chloroplast glycolipids, monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG) (PubMed:25203210). A number of isoforms are produced. According to EST sequences. Ubiquitously expressed at basal level. The ankyrin repeats (ANK) mediate interactions with hexoses-containing lipids present in organellar membranes (e.g. chloroplast), such as monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG). Lethal chlorotic phenotype when homozygote (PubMed:20215589). Reduced levels of chloroplast proteins, including outer envelope membrane (OEM) proteins. Defective chloroplast biogenesis (PubMed:18193034). Reduced APX3 levels and reduced targeting of APX3 to peroxisomes. Compromised peroxisomal function leading to increased sensitivity to aminotriazole during seed germination and shorter hypocotyls in darkness in the absence of sucrose (PubMed:20215589). Extended N-terminus.