For
more than two decades, Prof. Randy
Schekman had been a Howard Hughes Medical
Institute Investigator at the University of California,
Berkeley. He and his collaborators made pioneering
breakthroughs and discoveries of targeted vesicular
transpor t in eukar yotic cel l s, and found that
malfunctions in yeast cells arose due to genetic
defects. In 2013, Prof. Schekman shared a Nobel
Prize in Physiology or Medicine with Prof. Thomas
Südhof, whom we interviewed back in the first issue
of
Science Focus
.
Prof. Schekman’s passion for science began
early. Stemming from a toy microscope that he
received as a gift, he would examine the water
retrieved from a nearby creek to find a world of
creatures swimming under the lens. His passion for
being a scientist was magnified when he saved
up enough money to purchase his first professional
microscope, a treasure held dear to him until he left
for university. Those findings would be reported in a
yearly independent science fair project. A career
path of research seemed natural.
For the past 20 years, Prof. Schekman has
been working on cell communication in the form
of an extracellular vesicle, or exosome, which
contains membrane proteins and a set of RNAs that
convey information to control signalling and gene
expression in a target cell. He found that exosomes
capture selected microRNAs that form on the
surface of an endosome inside a donor cell. Thus,
Prof. Schekman’s lab has devised a biochemical
approach to study the mechanism of RNA sorting
into exosomes, but the role of the extracellular
RNA contained within exosomes that delivers such
information remains uncertain.
Their research has helped the biotechnology
industry make significant advances. The knowledge
of transport and communication of cells reveal
ways in which drug delivery can be made more
streamlined and efficient. Insulin and human growth
hormone, for instance, can be released by yeast.
Additionally, their mapping identified how nerve
cells release neurotransmitters. The research has far-
reaching future implications as well, particularly in
the application of treating metastatic cancer, or the
development of progressive neurological
disorders such as Alzheimer’s disease
and Parkinson’s disease. According
to Prof. Schekman, it is hopeful that
exosomes could be engineered
to deliver small molecules or RNAs
that control pathological processes
in targeted cells.
Prof. Schekman’s philosophy
for facing the inevitable setbacks
and difficulties in research is to
maintain a patient attitude and
to always meticulously plan in case
one approach fails.
It is easy to become
frustrated with the usual failure
of experiments, but one must remain
motivated by the main goals
and approaches, and be willing to
re-examine an approach
to find a new way forward.
Not surprisingly, Prof. Schekman has received
generous and continuous support for his research
from the U.S. National Science Foundation, the U.S.
National Institutes of Health and the Howard Hughes
Medical Institute. It is likely that he will continue to
work on membrane assembly, vesicular transport
and secretory pathways until he chooses to retire.
My keenest interest is in
establishing the molecular basis
of miRNA sorting into exosomes and
to seek evidence for or against a role
for the small RNAs within exosomes
in delivering information from a
donor to a target cell.
蘭
迪
•
謝克曼博士是加州大學柏克萊分校教授，同
時任職霍華德
•
休斯醫學研究所超過20年。他與合作者在真
核細胞的靶向囊泡運輸研究方面，作出了開拓性的貢獻，並
且發現遺傳缺陷造成酵母細胞的功能障礙。謝克曼教授與
Extracellular
Space
Cytoplasm
