Transient concentration of a gamma-tubulin-related protein with a pericentrin-related protein in the formation of basal bodies and flagella during the differentiation of Naegleria gruberi.
The distribution of two proteins in Naegleria gruberi, N-gammaTRP (Naegleria gamma-tubulin-related protein) and N-PRP (Naegleria pericentrin-related protein), was examined during the de novo formation of basal bodies and flagella that occurs during the differentiation of N. gruberi. After the initiation of differentiation, N-gammaTRP and N-PRP began to concentrate at the same site within cells. The percentage of cells with a concentrated region of N-gammaTRP and N-PRP was maximal (68%) at 40 min when the synthesis of tubulin had just started but no assembled microtubules were visible. When concentrated tubulin became visible (60 min), the region of concentrated N-gammaTRP and N-PRP was co-localized with the tubulin spot and then flagella began to elongate from the region of concentrated tubulin. When cells had elongated flagella, the concentrated N-gammaTRP and N-PRP were translocated to the opposite end of the flagellated cells and disappeared. The transient concentration of N-gammaTRP coincided with the transient formation of an F-actin spot at which N-gammaTRP and alpha-tubulin mRNA were co-localized. The concentration of N-gammaTRP and formation of the F-actin spot occurred without the formation of microtubules but were inhibited by cytochalasin D. These observations suggest that the regional concentration of N-gammaTRP and N-PRP is mediated by actin filaments and might provide a site of microtubule nucleation for the assembly of newly synthesized tubulins into basal bodies and flagella.
Suh
Mi Ra
MR
Department of Biology and Institute of Bioscience and Biotechnology, Yonsei University, Seoul 120-749, Korea.
Han
Ji Woong
JW
No
Yi Ran
YR
Lee
JooHun
J
D000199:Actins / Q000378:metabolism; D000818:Animals; D000941:Antigens / Q000032:analysis* / Q000502:physiology; D002454:Cell Differentiation; D002502:Centrioles / Q000737:chemistry*; D015638:Cytochalasin D / Q000378:metabolism; D005407:Flagella / Q000737:chemistry* / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000145:classification; D009253:Naegleria / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D015800:Protozoan Proteins / Q000032:analysis* / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D014404:Tubulin / Q000032:analysis* / Q000737:chemistry / Q000502:physiology
D000199:Actins; D000941:Antigens; D008869:Microtubule-Associated Proteins; D015800:Protozoan Proteins; D012333:RNA, Messenger; D014404:Tubulin; C086178:pericentrin; D015638:Cytochalasin D