ããŒãã³ãœã³ç ç å ã¿ã³ãã¯è³ªÂ LRRK2 ã®æŽ»æ§åãããããæ©æ§ã解æ
çºè¡šã®ãã€ã³ã
1.ããŒãã³ãœã³ç ã«ãããŠç°åžžãªæŽ»æ§åã瀺åãããç å ã¿ã³ãã¯è³ªãLRRK2ãã®æŽ»æ§å
ããããããååã¡ã«ããºã ãæããã«ããŸããã
2.LRRK2 ã®æŽ»æ§åã¯ããªãŒããã¡ãžãŒã«é¡äŒŒãããATG8 äžéèçµåæ©æ§ããä»ããŠã
ã现èå°åšå®ã§ãããªãœãœãŒã äžã«Â LRRK2 ãå±åšåããããšã«ããçããããšãçºèŠã
ããŸããã
3.æ¬ç 究ææã¯ãããŒãã³ãœã³ç ã«ããã LRRK2 ç°åžžæŽ»æ§åãé©åã«å¶åŸ¡ããããšã§ã
ãæ°ããªæ ¹æ¬çæ²»çæ³ã®éçºã«ã€ãªããããšãæåŸ ãããŸãã
LRRK2 掻æ§åã®ã¡ã«ããºã
æŠèŠ
ãæ±äº¬å€§åŠå€§åŠé¢å»åŠç³»ç 究ç§ã»ç¥çµç çåŠåéã®æ¡åç¥æš¹è¬åž«ãæ±å£æºä¹å€§åŠé¢ç(ç 究åœæãçŸ:ååçç©åŠåéå©æ)ãæ«»äºãŸããç¹ä»»ç 究å¡ã岩åªåšææãã®ã°ã«ãŒãã¯ãããŒãã³ãœã³ç (PD)ã®ç å ã¿ã³ãã¯è³ªÂ LRRK2(泚1)ã现èå°åšå®ã§ãããªãœãœãŒã (泚2)ãžã®ã¹ãã¬ã¹ã«å¿çããŠæŽ»æ§åããååæ©æ§ãæããã«ããŸããã
LRRK2 ã¯å®¶ææ§ããã³å€çºæ§Â PD ã«ããããã¿ã³ãã¯è³ªãªã³é žåé µçŽ ã§ããããã®ç°åžžãªæŽ»æ§åã PD ã®èæ¯ã«ããããšã瀺åãããŠããŸããã掻æ§åã®ååã¡ã«ããºã ãæ矩ã«ã€ããŠã¯å€ããäžæã§ããã
ç 究ã°ã«ãŒãã¯ããªãœãœãŒã ã«ã¹ãã¬ã¹ãè² è·ãããšÂ LRRK2 ã掻æ§åãããšããçºèŠããã£ãããšããŠããªãœãœãŒã å¶åŸ¡æ©æ§ãšã®é¢é£ãæ€èšããçµæã现èå èªå·±å解çµè·¯ã§ãããªãŒããã¡ãžãŒã«é¡äŒŒãããATG8 äžéèçµåæ©æ§ã(泚3)ã LRRK2 ãå¶åŸ¡ããããšãèŠåºããŸããããã®æ©æ§ã¯Â LRRK2ããªãœãœãŒã èäžã«å±åšåãããããšã§æŽ»æ§åããçµæãšããŠãªãœãœãŒã ã®åœ¢æ 調ç¯ãå 容ç©æŸåºã«è³ãããšãåãããŸããã
ãããã®çµæã¯ãLRRK2 ã®ç°åžžæŽ»æ§åæ©æ§ã®ç解ã«ã€ãªãããšãšãã«ããã®ã¡ã«ããºã ãžã®ä»åšã PD ã®æ²»çæŠç¥ã«ãªãå¯èœæ§ã瀺ããã®ã§ãã
Â
çºè¡šå 容
ãããŒãã³ãœã³ç (PD)ã¯è幎æã«çºçãã代衚çãªç¥çµé£ç ã§ããã65 æ³ä»¥äžã®ããã 100人ã«1人ããµãããåäœç·©æ ¢ãç匷åãªã©ã®éåçç¶ãåããçŸæ£ã§ãã
ãè³å ã®ãããã³ãè£å ãããªã©ã®å¯ŸåŠçæ³ã¯æ®åããŠãããã®ã®ãç¥çµçŽ°èã®å€æ§ãæ»ãã®ãã®ãæããæ ¹æ¬çæ²»çæ³ã¯æªã ååšããŸãããPD ã®äžéšã«ã¯éºäŒæ§ã«çºçããçäŸãååšãããã®åå éºäŒåãšããŠã2004 幎ã«Â LRRK2 (leucine-rich repeat kinase 2)ãåå®ãããŸãããLRRK2 ã¯ã¿ã³ãã¯è³ªãªã³é žåé µçŽ (ãããŒãŒ)ã§ããã现èå 㧠Rab(泚4)ãšåŒã°ããã¿ã³ãã¯è³ªãã¡ããªãŒã®äžçŸ€(Rab10, Rab8 ãªã©)ããªã³é žåããŸããé¡æ§éºäŒæ§ PD ã®åå ãšãªã LRRK2 éºäŒåã®å€ç°ã¯LRRK2 ã®é µçŽ 掻æ§(Rab ãªã³é žå掻æ§)ãé¡èã«äžæãããããšãç¥ãããŠããŸããããã«ãLRRK2 éºäŒåã®å€åã¯Â PD ã®å€§å€æ°ãå ããå€çºæ§Â PD ã®çºçãªã¹ã¯ã«ãé¢ããããšãå€çºæ§Â PDã®å°ãªããšãäžéšã«ãããŠÂ LRRK2 ã®é µçŽ 掻æ§ãäžæããŠããããšã瀺ãããŠããŸããåŸã£ãŠãLRRK2 ã¯Â PD ã«é¢ããæéèŠååã®1ã€ã§ãããšèšããŸããäžæ¹ãçäœã«ãããŠÂ LRRK2 ã®é µçŽ 掻æ§ãå®å šã«é»å®³ãããšã现èå°åšå®ã§ãããªãœãœãŒã ã®é¡èãªè¥å€§åãçããããšãç¥ãããŠãããLRRK2 ã¯çççã«ãªãœãœãŒã ã®ã¡ã³ããã³ã¹ã«éèŠãªæ©èœãæããŠããããšã瀺åãããŠããŸããåŸã£ãŠãPD ã®æ²»çæŠç¥ãèããããã§ã¯Â LRRK2 é µçŽ æŽ»æ§ã®é©åãªå¶åŸ¡ãéµã«ãªããšèããããŸãã
ç 究ã°ã«ãŒãã¯ãããŸã§ã«ããªãœãœãŒã ã«èç©ããŠéç©èŒã¹ãã¬ã¹ãäžããæ§è³ªãæããã¯ãããã³(泚5)ãªã©ã®ååç©ã现èã«æäžãããšãLRRK2 ã掻æ§åããããšãèŠåºããŠããŸãããä»åãã¯ãããã³æäžæã«ããã LRRK2 ã®çŽ°èå å±åšã詳现ã«èŠ³å¯ããçµæãè¥å€§åãããªãœãœãŒã ã®äžéèäžã§Â LRRK2 ã LC3(泚6)ãšåŒã°ããã¿ã³ãã¯è³ªãšå ±å±åšããŠããããšãèŠåºããŸãã(å³1)ã
å³1
ãªãœãœãŒã äžéèäžã«éç©ãã LRRK2 ãšÂ LC3GFP-LC3(ç·è²èå )ãšÂ mCherry-LRRK2(èµ€è²èå )ãçºçŸããã HEK293 现èã«ã¯ãããã³ãæäžããLC3 LRRK2 ã®çŽ°èå å±åšãå -é»åçžé¢é¡åŸ®é¡æ³(CLEM)ã«ãã芳å¯ããã
ç¢å°ã¯ LRRK2/LC3 äž¡éœæ§ã®äžéèæ§é ã瀺ãã察æ¯ãšããŠãªãŒããã¡ãŽãœãŒã è(é»ç¢å ãäºéè)ãæ žè(çœç¢å ãäºéè)ã瀺ããã
ãLC3 ã¯Â ATG8(泚6)ãšç·ç§°ãããã¿ã³ãã¯è³ªçŸ€ã®1ã€ã§ãããATG8 ã¯çŽ°èå èªå·±å解çµè·¯ã§ãããªãŒããã¡ãžãŒã®ããŒã«ãŒååãšããŠããç¥ãããŠããŸããéåžžãATG8 ã¯ãªãŒããã¡ãžãŒã®éã«åœ¢æãããè質äºéèãããªãéé¢è(ãªãŒããã¡ãŽãœãŒã )ã«å±åšããŸãããLRRK2 ãšã®å ±å±åšæã«ã¯äžéèäžã«ååšããŠããããšãããè¿å¹Žå ±åããããATG8 äžéèçµåæ©æ§ããåããŠããå¯èœæ§ãèããããŸãããATG8 äžéèçµåæ©æ§ã¯ããªãŒããã¡ãžãŒã®éå§ã«å¿ é ã®å å矀ã§ã¯èªå°ãããããããããªãœãœãŒã ã®Â pH äžæãæç¥ããŠäœåãããªãœãœãŒã èã¿ã³ãã¯è³ªÂ V-ATPase ãšããã®çžäºäœçšçžæã§ãã ATG16L1 ã®Â WD40 ãã¡ã€ã³ãšåŒã°ããæ§é ãå¿ èŠãšããŸãã现èçç©åŠçã»çååŠçã»éºäŒåŠç解æãããLRRK2 ã®ãªãœãœãŒã å±åšåãšããã«äŒŽã掻æ§åã¯Â ATG8 äžéèçµåæ©æ§ã«ãã£ãŠä»åšãããããšã瀺ãããŸãã(å³2)ãããã«ãã®ã¡ã«ããºã ã¯ãã¹ãã¬ã¹ãåãããªãœãœãŒã ã®è¥å€§åãæå¶ãããªãœãœãŒã å 容ç©ã现èå€ã«æŸåºããã圹å²ãæããããšãåãããŸãã(å³2)ã
å³2: LRRK2 掻æ§åãããããååã¡ã«ããºã ãšãã®åœ¹å²
ãªãœãœãŒã ãžã®ã¹ãã¬ã¹ã«ãããpH äžæãæ€ç¥ããŠäœåãããªãœãœãŒã èã¿ã³ãã¯è³ªÂ V-ATPase ãšãã®çžäºäœçšçžæ ATG16L1 ã®Â WD40 ãã¡ã€ã³ãä»ãããATG8 äžéèçµåæ©æ§ãã ATG8 ãšÂ LRRK2 ããªãœãœãŒã èäžã«ãªã¯ã«ãŒããããLRRK2 ã¯ãªãœãœãŒã èäžã§æŽ»æ§åããŠÂ Rab10 ããªã³é žåãããªãœãœãŒã ã®åœ¢æ ç¶æãšãªãœãœãŒã å 容ç©ã®çŽ°èå€åæ³ãããããããã
ã以äžã®çµæãããLRRK2 ã®æŽ»æ§åãšãã®çµæçãããªãœãœãŒã ã¹ãã¬ã¹å¿çãããããååã¡ã«ããºã ãæãããšãªããŸãããPD ãé¡çžã®ç¥çµå€æ§çŸæ£ã«ãããŠã¯ãããŸã§ããªãœãœãŒã ã®æ©èœçç°åžžãå€ãææãããŠããããŸããLRRK2 以å€ã«ãè€æ°ã®ãªãœãœãŒã é¢é£éºäŒåã PDã®çºçãªã¹ã¯ã«é¢ããããšã瀺ãããŠããŸãã
æ¬ç 究ã§èŠåºããã¡ã«ããºã ã PD ã«ãããLRRK2 ã®ç°åžžæŽ»æ§åã«é¢ããããšãæ³å®ãããæ¬ã¡ã«ããºã ãžã®ä»åšã LRRK2 掻æ§ã®é©åãªå¶åŸ¡ã«ã€ãªããããšãæåŸ ãããŸãã
çšèªè§£èª¬
(泚1) LRRK2
Leucine-rich repeat kinase 2 ã®ç¥ãã©ãŒã¯ã»ãã¥ãŒãšçºé³ããããåžžæè²äœé¡æ§éºäŒæ§Â PDã«ãããŠæãé«é »åºŠã«å€ç°ãèªããéºäŒåã§ããã2004 幎ã«æ¬§å·ã®ç 究ã°ã«ãŒãã«ããåå®ããããèšåºããã³ç çåŠçç¹åŸŽã¯ãæ人çºçã®å€çºäŸÂ PD ã«é¡äŒŒããŠãããLRRK2 ã¿ã³ãã¯è³ªã¯è€æ°ã®æ©èœãã¡ã€ã³ãæãã巚倧ãªã¿ã³ãã¯è³ªãªã³é žåé µçŽ (ãããŒãŒ)ã§ãããäž»ã«Â Rab ã¿ã³ãã¯è³ªããªã³é žåãããLRRK2 ãããŒãŒæŽ»æ§é»å®³å€Â BIIB122/DNL151 ã¯ç±³åœÂ Biogen 瀟ãšÂ Denali瀟ã«ãããæ©æ PD æ£è ã察象ãšãã第 IIb çžæ²»éšããã³Â LRRK2 å€ç°ä¿æ PD æ£è ã察象ãšãã第 III çžæ²»éšãé²ããããŠããã
(泚2) ãªãœãœãŒã
çæ žçç©ã®çŽ°èå°åšå®ã®1ã€ã§ãããå éšã®Â pH ã 5 ååŸã®é žæ§ã«ä¿ãããäžéèãããªãæ§é äœã§ãããçš®ã ã®å æ°Žåè§£é µçŽ ãå«ãã§ãããäž»ã«çŽ°èå å€æåã®å解ã»åå©çšè£ 眮ãšããŠæ©èœããã»ãã现èè修埩ãå ç«å¿çãªã©ã«ãéèŠãªåœ¹å²ãæããã
(泚3) ATG8 äžéèçµåæ©æ§
è±æè¡šèšã§ CASM (conjugation of ATG8 to endolysosomal single membranes)ãšåŒç§°ãããŠãããATG8 ã¿ã³ãã¯è³ªããšã³ããªãœãœãŒã ã®äžéèã«å±åšåããçŸè±¡ããã³ãã®æ©æ§ãæããATG8 ã¯ãªãŒããã¡ãžãŒã®èªå°æã«åœ¢æãããè質äºéèãããªãéé¢èã«å±åšåããããšãããç¥ãããŠããããã®çŸè±¡ãšåºå¥ããããã«Â CASM ãšããåŒç§°ãè¿å¹Žå®çããã以åã¯Â noncanonical autophagy(éå žåçãªãŒããã¡ãžãŒ)ãšãåŒã°ããŠãããã现èå å解ã䌎ããªããããªãŒããã¡ãžãŒãšã¯ç°ãªããã¡ã«ããºã ãšããŠããªãœãœãŒã èäžã®ãããã³ãã³ã VATPase ãšãã®çžäºäœçšå å ATG16L1 ã®Â WD40 ãã¡ã€ã³ãä»ãããV-ATPase-ATG16L1 軞ããé¢ããããšã瀺ãããŠããã
(泚4) Rab
äœååé G ã¿ã³ãã¯è³ª(ã°ã¢ãã³ãã¯ã¬ãªããçµåã¿ã³ãã¯è³ª)ã§ããããããããŠã¹ã§ã¯60 çš®é¡ä»¥äžã®ã¢ã€ãœãã©ãŒã (é¡äŒŒã®ã¿ã³ãã¯è³ª)ãããªãäž»èŠãªãã¡ããªãŒåå矀ãæããäž»ã«çŽ°èå å°è茞éãåžãããã®æ©èœã¯äž»ã« GTP(ã°ã¢ãã·ã³äžãªã³é ž)ã«çµåãã掻æ§åãšGDP(ã°ã¢ãã·ã³äºãªã³é ž)ã«çµåããäžæŽ»æ§åã®éããµã€ã¯ã«ããããšã«ããå¶åŸ¡ãããã2016 幎ã«å ¥ããäžéšã®Â Rab ã现èå ã§Â LRRK2 ã«ãã£ãŠãªã³é žåãããããšãããã«ãã Rab ã®GTP-GDP çµåãµã€ã¯ã«ãè¿œå çã«å¶åŸ¡ãããããšãå ±åãããã
(泚5) ã¯ãããã³
å¡©åºæ§ãã€äž¡èŠªåªæ§ã®äœååååç©ã§ããããã®åŒ±å¡©åºãšããŠã®æ§è³ªãããªãœãœãŒã ã«ç§»è¡åŸãããã³ãåãåã£ãŠãªãœãœãŒã å ã«èç©ãããªãœãœãŒã ã®è¥å€§åã»pH äžæã»éç©èŒããããããç 究ã§ã¯äžè¬ã«ãªãœãœãŒã é»å®³å€ãšããŠçšãããããèšåºã§ã¯äž»ã«æãã©ãªã¢å€ãšããŠçšãããããã網èé害ãªã©ã®å¯äœçšãç¥ãããŠããã
(泚6) LC3/ATG8
LC3 ã¯é µæ¯ã®Â Atg8 ã¿ã³ãã¯è³ªã®åºä¹³åç©ã«ããããªã«ãœãã°(çžåœåå)ã§ãããããã§ã¯LC3 ãå«ã6ã€ã®é¡äŒŒã¿ã³ãã¯è³ªããªã«ãœãã°ã§ãããããããã¯ãŸãšããŠÂ ATG8 ãšãåŒç§°ãããããªãŒããã¡ãžãŒã®ããŒã«ãŒååãšããŠåºãèªç¥ãããŠãããè質修食ãåããŠéé¢è(ãªãŒããã¡ãŽãœãŒã ãäºéè)ã«å±åšåãããè¿å¹Žãã¯ãããã³æäžæãªã©ã®ãªãœãœãŒã ã¹ãã¬ã¹äžã§ã¯ãšã³ããªãœãœãŒã ã®äžéèã«ãå±åšåããããšãç¥ãããããã«ãªã£ãã