Kay R R, Taylor G W, Jermyn K A, Traynor D
MRC Laboratory of Molecular Biology, Cambridge, U.K.
Biochem J. 1992 Jan 1;281 ( Pt 1)(Pt 1):155-61. doi: 10.1042/bj2810155.
DIF-1 [Differentiation-Inducing Factor 1; 1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)hexan-1-one] is a novel chlorinated signal molecule that induces stalk-cell differentiation during development of Dictyostelium discoideum. Here we introduce the use of the radioisotope 36Cl to label DIF-1 and other low-Mr chlorinated compounds produced during development. H.p.l.c. and t.l.c. were used to resolve the labelled compounds. We find the following. (1) At least 14 dialysable 36Cl-labelled compounds are released into the medium by cells labelled continuously through development with Na36Cl. (2) The compounds can be classified into two major groups according to their times of accumulation in development. The early group of compounds starts accumulating at the end of aggregation, co-ordinately with DIF-1; the late group is only made at the end of development, by mature fruiting bodies. There may also be an intermediate group made during culmination. (3) The early group of compounds has been identified as comprising DIF-1 and seven of its metabolites by co-chromatography with the authentic compounds. These metabolites had previously only been recognized in suspensions of living cells incubated with exogenous DIF-1. Their detection here, from cells undergoing normal development, suggests that endogenous DIF-1 is metabolized in normal development in much the same way as is DIF-1 added to cells in suspension. (4) The intermediate and late groups of compounds are not obvious DIF-1 metabolites. They may have some role unconnected with DIF signalling. (5) A group of 36Cl-labelled late compounds remain cell-associated after washing of the fruiting bodies, and these are greatly enriched in stalk, compared with spore, cells. (6) Other slime-mould species were labelled with 36Cl. All three tested, namely D. mucoroides, D. vinaceo-fuscum and P. violaceum, also produced chloro compounds. D. mucoroides produced DIF-1 by the criterion of h.p.l.c. co-elution with authentic DIF-1. A developmentally regulated metabolism of chlorinated compounds may therefore be widespread amongst slime moulds. To our knowledge, labelling with 36Cl in vivo has not been reported before and provides a powerful general method for investigating chlorinated compounds in diverse organisms.
分化诱导因子1 [Differentiation-Inducing Factor 1；1-(3,5-二氯-2,6-二羟基-4-甲氧基苯基)己烷-1-酮] 是一种新型氯化信号分子，可在盘基网柄菌发育过程中诱导柄细胞分化。在此，我们介绍使用放射性同位素36Cl标记分化诱导因子1以及发育过程中产生的其他低分子量氯化化合物。采用高效液相色谱法（H.p.l.c.）和薄层层析法（t.l.c.）分离标记化合物。我们发现以下几点：(1) 通过用Na36Cl在发育过程中持续标记细胞，至少有14种可透析的36Cl标记化合物被释放到培养基中。(2) 根据这些化合物在发育过程中的积累时间，可将其分为两大类。早期积累的化合物在聚集末期开始积累，与分化诱导因子1同步；晚期积累的化合物仅在发育末期由成熟子实体产生。在发育高峰期可能也会产生一组中间型化合物。(3) 通过与标准化合物共色谱分析，已确定早期积累的化合物包括分化诱导因子1及其七种代谢产物。这些代谢产物以前仅在与外源性分化诱导因子1一起孵育的活细胞悬液中被识别。在此从正常发育的细胞中检测到它们，表明内源性分化诱导因子1在正常发育中的代谢方式与添加到悬浮细胞中的分化诱导因子1大致相同。(4) 中间型和晚期积累的化合物不是明显的分化诱导因子1代谢产物。它们可能具有一些与分化诱导因子信号传导无关的作用。(5) 一组36Cl标记的晚期化合物在子实体洗涤后仍与细胞相关，与孢子细胞相比，这些化合物在柄细胞中大量富集。(6) 用36Cl标记其他黏菌物种。所测试的三种，即黏液网柄菌、酒色暗柄菌和紫色发网菌，也产生含氯化合物。根据高效液相色谱法与标准分化诱导因子1共洗脱的标准，黏液网柄菌产生分化诱导因子1。因此，氯化化合物的发育调控代谢可能在黏菌中广泛存在。据我们所知，以前尚未报道过体内用36Cl标记的情况，这为研究不同生物体中的氯化化合物提供了一种强大的通用方法。
