Observations on acid phosphatase in <i>Mayorella palestinensis</i>

Lasman, M.

doi:10.1002/jcp.1040690205

Cited by 12 publications

(5 citation statements)

References 19 publications

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“…In a report on peroxisomes (20), we mentioned the intracellular localization of acid phosphatase. Mayorella palestinensis, a closely related species, has been studied in some detail and its intracellular amylase, phosphatase and proteinase partly characterized (7, 13,23). As in the present findings, these enzymes all had an acid pH optimum.…”

Section: Resultssupporting

confidence: 80%

Lysosomal Hydrolases in Acanthamoeba sp.

Müller

1969

The Journal of Protozoology

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SYNOPSIS. Homogenates of axenic Acanthamoeba sp. had ribonuclease, phosphatase, proteinase, α‐glucosidase, β‐N‐acetylglucosaminidase, and β‐glucuronidase activities; all had acid pH optima. After isopycnic density‐gradient centrifugation all showed the same relatively broad and unimodal distribution pattern, with a peak at a density of 1.17. This differs from the distribution of mitochondrial malate dehydrogenase and of peroxisomal urate oxidase and catalase. The findings are believed to reflect the occurrence of lysosomes in Acanthamoeba.

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Section: Resultssupporting

confidence: 80%

Lysosomal Hydrolases in Acanthamoeba sp.

Müller

1969

The Journal of Protozoology

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“…A decrease in cellular content of several biological molecules (6,18,28) and the appearance of autophagic vacuoles (3, 7-9, 13, 16) have been described during cyst differentiation, both observations suggesting the participation of lysosomes in the process. The activity of lysosomal enzymes has been known to increase, transiently, during encystment of several soil amoebae (1, 10,12). Similar increases have been reported to occur in a cellular slime mold in conjunction with protein synthesis (20,21,23).…”

mentioning

confidence: 67%

“…These results suggest the participation of lysosomes during this early stage. A transient increase of lysosomal enzyme level also has been reported during early phases of cyst differentiation in soil amoebae and in a cellular slime mold (1, 10,12,20,21,23). Further studies, however, are needed to clarify the role of lysosomes on cyst differentiation.…”

Section: Discussionmentioning

confidence: 91%

Changes in Two Acid Hydrolase Levels During Cyst Differentiation of a Ciliate, Histriculus muscorum1

Sendo

Matsusaka

1982

The Journal of Protozoology

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Cellular levels of protein and two acid hydrolases, acid phosphatase (EC 3.1.3.2) and acid proteinase, were followed during cyst differentiation, arbitrarily divided into five stages, in the ciliate Histriculus muscorum Kahl. Extracellular enzyme activities were also measured. Protein content decreased gradually during cyst differentiation. In mature cysts the protein content was ca. 60% that of stationary phase organisms. The activities of both acid hydrolases remained unchanged during stage 1 and then decreased gradually; acid proteinase decreased more rapidly. Both enzymes remained slightly active in the mature cysts. The acid proteinase activity of stage 1 was reduced by cycloheximide treatment at time zero, whereas the enzyme was no longer sensitive to the inhibitor when treated at 1.5 h (late stage 1) after the first wash with encysting medium. Acid phosphatase activity was insensitive to the inhibitor. Extracellular release of acid phosphatase increased linearly at least until stage 5, although the extracellular release of acid proteinase was not detected. Cycloheximide blocked the extracellular release of acid phosphatase after stage 1. These results suggest that de novo synthesis of acid proteinase occurs during stage 1 and that lysosomes may play an important role during early stages of cyst differentiation.

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“…The importance of this degradative phase suggests that encystation is a process in which it would be reasonable to expect lysosomal activity to play a significant role and there is now some evidence for the participation of autolysosomes in cyst-formation in Acanthamoeba sp. (Bowers & Korn, 1969) and in another amoeba, Mayorella palestinensis (Lasman, 1967). As encystation can now be investigated under reasonably controlled experimental conditions it would seem to present a suitable system for the study of the control of lysosomal activity in developmental processes.…”

Section: Introductionmentioning

confidence: 99%

Lysosomal Activity and its Control in Encysting Hartmannella castellanii

Aj¹,

Sm²

1969

Journal of General Microbiology

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S U M M A R YA latent, non-specific phosphatase of Hartmannella castellanii with an optimum pH of 4-0 has been investigated. The latency could be released in cell-free homogenates by treatment with Triton x roo, freezing and thawing, refrigeration or carbon tetrachloride. It seems likely that this enzyme is attached to a sub-cellular organelle as it was largely sedimentable when homogenates were prepared in media containing sucrose.During encystation of the amoebae under controlled conditions there was no appreciable change in the levels of total phosphatase activity measured in frozen-thawed extracts, but there were quite large increases in free activities of fresh, unfrozen preparations. Inhibitors and promoters of encystation were also found to affect the levels of phosphatase activity in the amoebae but did not affect its sedimentability which persisted throughout the initial degradative phase of encystment.Incubation of homogenates of Hartmannella decreased the latency of the acid phosphatase but this activation could be modified by substances which are known to affect the encystation responses of the amoebae.It is concluded that the degradative phase of encystation is due to the activation of hydrolytic enzymes within sedimentable compartments of the amoebae and is not the result of hydrolases being released from these compartments. It seems likely that agents which are capable of promoting encystation may do so by inducing activation of lysosomal enzymes.

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Observations on acid phosphatase in Mayorella palestinensis

Cited by 12 publications

References 19 publications

Lysosomal Hydrolases in Acanthamoeba sp.

Lysosomal Hydrolases in Acanthamoeba sp.

Changes in Two Acid Hydrolase Levels During Cyst Differentiation of a Ciliate, Histriculus muscorum1

Lysosomal Activity and its Control in Encysting Hartmannella castellanii

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