{"id":5981,"date":"2026-10-19T09:48:18","date_gmt":"2026-10-19T09:48:18","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-josue-a-ballesteros-alvarez\/"},"modified":"2026-10-19T09:48:18","modified_gmt":"2026-10-19T09:48:18","slug":"doktorsvorn-i-lif-og-laeknavisindum-josue-a-ballesteros-alvarez","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-josue-a-ballesteros-alvarez\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00edf- og l\u00e6knav\u00edsindum – Josue A. Ballesteros Alvarez"},"content":{"rendered":"
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Fimmtudaginn 10. jan\u00faar ver Josue A. Ballesteros Alvarez doktorsritger\u00f0 s\u00edna \u00ed l\u00edf- og l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0 Net bHLHZip umritunar\u00fe\u00e1tta \u00ed sortu\u00e6xlum: Samstarf milli MITF, TFEB og TFE3. A network of bHLHZip transcription factors in melanoma: Interactions of MITF, TFEB and TFE3.<\/strong>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/p>\n

Andm\u00e6lendur eru dr. Marie Dominique Galibert, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Rennes \u00ed Frakklandi, og dr. Zophon\u00edas Oddur J\u00f3nsson, pr\u00f3fessor \u00ed sameindaerf\u00f0afr\u00e6\u00f0i vi\u00f0 L\u00edf-og umhverfisv\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands.<\/p>\n

Umsj\u00f3narkennari og lei\u00f0beinandi var dr. Eir\u00edkur Steingr\u00edmsson, pr\u00f3fessor vi\u00f0 L\u00e6knadeild, og me\u00f0lei\u00f0beinandi var Margr\u00e9t Helga \u00d6gmundsd\u00f3ttir, a\u00f0junkt vi\u00f0 L\u00e6knadeild. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefnd J\u00f3runn Erla Eyfj\u00f6r\u00f0, pr\u00f3fessor emeritus vi\u00f0 L\u00e6knadeild, \u00de\u00f3rarinn Gu\u00f0j\u00f3nsson, pr\u00f3fessor vi\u00f0 L\u00e6knadeild og Lars R\u00f6nnstrand, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Lundi.<\/p>\n

Engilbert Sigur\u00f0sson, pr\u00f3fessor og forseti L\u00e6knadeildar H\u00e1sk\u00f3la \u00cdslands, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed Ver\u00f6ld-H\u00fasi Vigd\u00edsar – VHV-023 og hefst kl. 13.00.<\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

Stj\u00f3rnpr\u00f3teinin MITF, TFEB, TFE3 og TFEC (stundum nefnd MiT-TFE \u00fe\u00e6ttirnir) tilheyra bHLHZip fj\u00f6lskyldu umritunar\u00fe\u00e1tta sem bindast DNA og stj\u00f3rna tj\u00e1ningu gena. MITF er mikilv\u00e6gt fyrir myndun og starfsemi litfruma en \u00e6ttingjar \u00feess, TFEB og TFE3, stj\u00f3rna myndun og starfsemi lys\u00f3s\u00f3ma og sj\u00e1lfs\u00e1ti. Sj\u00e1lfs\u00e1t gegnir mikilv\u00e6gu hlutverki \u00ed starfsemi fruma en getur einnig haft \u00e1hrif \u00e1 myndun og me\u00f0h\u00f6ndlun sj\u00fakd\u00f3ma. \u00cd verkefni \u00feessu var samstarf MITF, TFE3 og TFEB pr\u00f3teinanna sko\u00f0a\u00f0 \u00ed sortu\u00e6xlisfrumum. \u00cd lj\u00f3s kom a\u00f0 \u00feessir \u00fe\u00e6ttir stj\u00f3rna tj\u00e1ningu hvers annars, b\u00e6\u00f0i beint og \u00f3beint. Pr\u00f3tein \u00feessi geta einnig mynda\u00f0 mistvenndir hvert me\u00f0 \u00f6\u00f0ru \u00ed \u00e6xlisfrumum en ekki me\u00f0 \u00f6\u00f0rum bHLHZip pr\u00f3teinum eins og MAX. \u00deriggja am\u00edn\u00f3s\u00fdru-sv\u00e6\u00f0i, sem er til sta\u00f0ar \u00ed HLH-Zip sv\u00e6\u00f0inu, er nau\u00f0synlegt fyrir \u00feessa tvenndarmyndun. Ni\u00f0ursta\u00f0a verkefnisins er a\u00f0 sambandi\u00f0 milli MITF, TFEB og TFE3 felst \u00ed \u00e1hrifum \u00e1 stj\u00f3rnun genatj\u00e1ningar, samstarfi pr\u00f3teina og \u00e1hrifum bo\u00f0lei\u00f0a \u00e1 sta\u00f0setningu \u00ed frumul\u00edff\u00e6rum. Mikilv\u00e6gt er a\u00f0 greina og skilja \u00feetta samband \u00ed sortu\u00e6xlum til a\u00f0 \u00f6\u00f0last betri skilning \u00e1 \u00fev\u00ed hvernig unnt er a\u00f0 hafa \u00e1hrif \u00e1 \u00feau ferli sem umritunar\u00fe\u00e6ttir \u00feessir stj\u00f3rna.<\/p>\n

Abstract<\/strong><\/p>\n

The transcription factors MITF, TFEB, TFE3 and TFEC (MiT-TFE) belong to the larger family of basic helix-loop-helix leucine zipper proteins that are able to bind DNA and regulate gene expression. MITF is crucial for melanocyte development and has been called a lineage specific oncogene in melanoma whereas its relatives, TFEB and TFE3 are involved in the biogenesis and function of lysosomes and autophagosomes, regulating cellular clearance pathways. Autophagy is a biological process that plays a prominent role in human disease and can also have an impact on the outcome of therapeutic approaches. This project investigated the interactions and cross-regulatory relationships of MITF, TFE3 and TFEB in melanoma cells. Like MITF, the TFEB and TFE3 genes are expressed in melanoma cells and tissues. They regulate each other\u2019s expression and they are able to heterodimerize in melanoma cells. However, they fail to interact with other members of the bHLH family such as MAX. Furthermore, we show that a three amino acid region present in the HLH-Zip region is responsible for dimerization specificity. The relationship between MITF, TFEB and TFE3 is complex and involves regulation of gene expression, protein-protein interactions resulting in complementary functions. It is important to further unravel this relationship in melanoma to gain a better understanding of the cross-regulatory mechanisms involved and how these factors regulate lysosomal function.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Josue A. Ballesteros Alvarez er f\u00e6ddur 21. j\u00fal\u00ed 1987 \u00ed Vigo \u00e1 Sp\u00e1ni. Hann \u00fatskrifa\u00f0ist me\u00f0 diploma-gr\u00e1\u00f0u \u00ed l\u00edfefnafr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3lanum \u00ed Salamanca \u00e1 Sp\u00e1ni 2012. Sem hluta af diploman\u00e1mi s\u00ednu vann hann eins \u00e1rs ranns\u00f3knaverkefni \u00e1 ranns\u00f3knastofu dr. Claudios Franceschi vi\u00f0 H\u00e1sk\u00f3lann \u00ed Bologna \u00e1 \u00cdtal\u00edu. Hann h\u00f3f doktorsn\u00e1m vi\u00f0 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2014. Foreldrar Josue eru \u00feau Luis Ballesteros Parente og Maria Consuelo \u00c1lvarez V\u00e1zquez. Josue stefnir \u00e1 frekari ranns\u00f3knir sem n\u00fddoktor vi\u00f0 Buck Institute of Research in Aging \u00ed Novato, Kaliforn\u00edu.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1168,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-01-10T13:00:00+00:00","_phd_date_end":"2019-01-10T16:00:00+00:00","_phd_location":"Ver\u00f6ld - H\u00fas Vigd\u00edsar VHV-023","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Net bHLHZip umritunar\u00fe\u00e1tta \u00ed sortu\u00e6xlum: Samstarf milli MITF, TFEB og TFE3. 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